syncthing/lib/model/model_test.go

// Copyright (C) 2014 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.

package model

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"math/rand"
	"os"
	"path/filepath"
	"runtime"
	"runtime/pprof"
	"sort"
	"strconv"
	"strings"
	"sync"
	"sync/atomic"
	"testing"
	"time"
	"unicode"
	"unicode/utf8"

	"github.com/syncthing/syncthing/lib/config"
	"github.com/syncthing/syncthing/lib/db"
	"github.com/syncthing/syncthing/lib/db/backend"
	"github.com/syncthing/syncthing/lib/events"
	"github.com/syncthing/syncthing/lib/fs"
	"github.com/syncthing/syncthing/lib/ignore"
	"github.com/syncthing/syncthing/lib/osutil"
	"github.com/syncthing/syncthing/lib/protocol"
	srand "github.com/syncthing/syncthing/lib/rand"
	"github.com/syncthing/syncthing/lib/testutils"
	"github.com/syncthing/syncthing/lib/versioner"
)

var testDataExpected = map[string]protocol.FileInfo{
	"foo": {
		Name:      "foo",
		Type:      protocol.FileInfoTypeFile,
		ModifiedS: 0,
		Blocks:    []protocol.BlockInfo{{Offset: 0x0, Size: 0x7, Hash: []uint8{0xae, 0xc0, 0x70, 0x64, 0x5f, 0xe5, 0x3e, 0xe3, 0xb3, 0x76, 0x30, 0x59, 0x37, 0x61, 0x34, 0xf0, 0x58, 0xcc, 0x33, 0x72, 0x47, 0xc9, 0x78, 0xad, 0xd1, 0x78, 0xb6, 0xcc, 0xdf, 0xb0, 0x1, 0x9f}}},
	},
	"empty": {
		Name:      "empty",
		Type:      protocol.FileInfoTypeFile,
		ModifiedS: 0,
		Blocks:    []protocol.BlockInfo{{Offset: 0x0, Size: 0x0, Hash: []uint8{0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14, 0x9a, 0xfb, 0xf4, 0xc8, 0x99, 0x6f, 0xb9, 0x24, 0x27, 0xae, 0x41, 0xe4, 0x64, 0x9b, 0x93, 0x4c, 0xa4, 0x95, 0x99, 0x1b, 0x78, 0x52, 0xb8, 0x55}}},
	},
	"bar": {
		Name:      "bar",
		Type:      protocol.FileInfoTypeFile,
		ModifiedS: 0,
		Blocks:    []protocol.BlockInfo{{Offset: 0x0, Size: 0xa, Hash: []uint8{0x2f, 0x72, 0xcc, 0x11, 0xa6, 0xfc, 0xd0, 0x27, 0x1e, 0xce, 0xf8, 0xc6, 0x10, 0x56, 0xee, 0x1e, 0xb1, 0x24, 0x3b, 0xe3, 0x80, 0x5b, 0xf9, 0xa9, 0xdf, 0x98, 0xf9, 0x2f, 0x76, 0x36, 0xb0, 0x5c}}},
	},
}

func init() {
	// Fix expected test data to match reality
	for n, f := range testDataExpected {
		fi, _ := os.Stat("testdata/" + n)
		f.Permissions = uint32(fi.Mode())
		f.ModifiedS = fi.ModTime().Unix()
		f.Size = fi.Size()
		testDataExpected[n] = f
	}
}

func TestMain(m *testing.M) {
	tmpName, err := prepareTmpFile(defaultFs)
	if err != nil {
		panic(err)
	}

	exitCode := m.Run()

	os.Remove(defaultCfgWrapper.ConfigPath())
	defaultFs.Remove(tmpName)
	defaultFs.RemoveAll(config.DefaultMarkerName)

	os.Exit(exitCode)
}

func prepareTmpFile(to fs.Filesystem) (string, error) {
	tmpName := fs.TempName("file")
	in, err := defaultFs.Open("tmpfile")
	if err != nil {
		return "", err
	}
	defer in.Close()
	out, err := to.Create(tmpName)
	if err != nil {
		return "", err
	}
	defer out.Close()
	if _, err = io.Copy(out, in); err != nil {
		return "", err
	}
	future := time.Now().Add(time.Hour)
	if err := os.Chtimes(filepath.Join("testdata", tmpName), future, future); err != nil {
		return "", err
	}
	return tmpName, nil
}

func createTmpWrapper(cfg config.Configuration) config.Wrapper {
	tmpFile, err := ioutil.TempFile("", "syncthing-testConfig-")
	if err != nil {
		panic(err)
	}
	wrapper := config.Wrap(tmpFile.Name(), cfg, events.NoopLogger)
	tmpFile.Close()
	return wrapper
}

func newState(cfg config.Configuration) *model {
	wcfg := createTmpWrapper(cfg)

	m := setupModel(wcfg)

	for _, dev := range cfg.Devices {
		m.AddConnection(&fakeConnection{id: dev.DeviceID, model: m}, protocol.HelloResult{})
	}

	return m
}

func TestRequest(t *testing.T) {
	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	// Existing, shared file
	res, err := m.Request(device1, "default", "foo", 6, 0, nil, 0, false)
	if err != nil {
		t.Fatal(err)
	}
	bs := res.Data()
	if !bytes.Equal(bs, []byte("foobar")) {
		t.Errorf("Incorrect data from request: %q", string(bs))
	}

	// Existing, nonshared file
	_, err = m.Request(device2, "default", "foo", 6, 0, nil, 0, false)
	if err == nil {
		t.Error("Unexpected nil error on insecure file read")
	}

	// Nonexistent file
	_, err = m.Request(device1, "default", "nonexistent", 6, 0, nil, 0, false)
	if err == nil {
		t.Error("Unexpected nil error on insecure file read")
	}

	// Shared folder, but disallowed file name
	_, err = m.Request(device1, "default", "../walk.go", 6, 0, nil, 0, false)
	if err == nil {
		t.Error("Unexpected nil error on insecure file read")
	}

	// Negative offset
	_, err = m.Request(device1, "default", "foo", -4, 0, nil, 0, false)
	if err == nil {
		t.Error("Unexpected nil error on insecure file read")
	}

	// Larger block than available
	_, err = m.Request(device1, "default", "foo", 42, 0, nil, 0, false)
	if err == nil {
		t.Error("Unexpected nil error on insecure file read")
	}
}

func genFiles(n int) []protocol.FileInfo {
	files := make([]protocol.FileInfo, n)
	t := time.Now().Unix()
	for i := 0; i < n; i++ {
		files[i] = protocol.FileInfo{
			Name:      fmt.Sprintf("file%d", i),
			ModifiedS: t,
			Sequence:  int64(i + 1),
			Blocks:    []protocol.BlockInfo{{Offset: 0, Size: 100, Hash: []byte("some hash bytes")}},
			Version:   protocol.Vector{Counters: []protocol.Counter{{ID: 42, Value: 1}}},
		}
	}

	return files
}

func BenchmarkIndex_10000(b *testing.B) {
	benchmarkIndex(b, 10000)
}

func BenchmarkIndex_100(b *testing.B) {
	benchmarkIndex(b, 100)
}

func benchmarkIndex(b *testing.B, nfiles int) {
	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	files := genFiles(nfiles)
	m.Index(device1, "default", files)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		m.Index(device1, "default", files)
	}
	b.ReportAllocs()
}

func BenchmarkIndexUpdate_10000_10000(b *testing.B) {
	benchmarkIndexUpdate(b, 10000, 10000)
}

func BenchmarkIndexUpdate_10000_100(b *testing.B) {
	benchmarkIndexUpdate(b, 10000, 100)
}

func BenchmarkIndexUpdate_10000_1(b *testing.B) {
	benchmarkIndexUpdate(b, 10000, 1)
}

func benchmarkIndexUpdate(b *testing.B, nfiles, nufiles int) {
	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	files := genFiles(nfiles)
	ufiles := genFiles(nufiles)

	m.Index(device1, "default", files)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		m.IndexUpdate(device1, "default", ufiles)
	}
	b.ReportAllocs()
}

func BenchmarkRequestOut(b *testing.B) {
	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	const n = 1000
	files := genFiles(n)

	fc := &fakeConnection{id: device1, model: m}
	for _, f := range files {
		fc.addFile(f.Name, 0644, protocol.FileInfoTypeFile, []byte("some data to return"))
	}
	m.AddConnection(fc, protocol.HelloResult{})
	m.Index(device1, "default", files)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		data, err := m.requestGlobal(context.Background(), device1, "default", files[i%n].Name, 0, 32, nil, 0, false)
		if err != nil {
			b.Error(err)
		}
		if data == nil {
			b.Error("nil data")
		}
	}
}

func BenchmarkRequestInSingleFile(b *testing.B) {
	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	buf := make([]byte, 128<<10)
	rand.Read(buf)
	mustRemove(b, defaultFs.RemoveAll("request"))
	defer func() { mustRemove(b, defaultFs.RemoveAll("request")) }()
	must(b, defaultFs.MkdirAll("request/for/a/file/in/a/couple/of/dirs", 0755))
	writeFile(defaultFs, "request/for/a/file/in/a/couple/of/dirs/128k", buf, 0644)

	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		if _, err := m.Request(device1, "default", "request/for/a/file/in/a/couple/of/dirs/128k", 128<<10, 0, nil, 0, false); err != nil {
			b.Error(err)
		}
	}

	b.SetBytes(128 << 10)
}

func TestDeviceRename(t *testing.T) {
	hello := protocol.HelloResult{
		ClientName:    "syncthing",
		ClientVersion: "v0.9.4",
	}
	defer func() { mustRemove(t, defaultFs.Remove("tmpconfig.xml")) }()

	rawCfg := config.New(device1)
	rawCfg.Devices = []config.DeviceConfiguration{
		{
			DeviceID: device1,
		},
	}
	cfg := config.Wrap("testdata/tmpconfig.xml", rawCfg, events.NoopLogger)

	db := db.NewLowlevel(backend.OpenMemory())
	m := newModel(cfg, myID, "syncthing", "dev", db, nil)

	if cfg.Devices()[device1].Name != "" {
		t.Errorf("Device already has a name")
	}

	conn := &fakeConnection{id: device1, model: m}

	m.AddConnection(conn, hello)

	m.ServeBackground()
	defer cleanupModel(m)

	if cfg.Devices()[device1].Name != "" {
		t.Errorf("Device already has a name")
	}

	m.Closed(conn, protocol.ErrTimeout)
	hello.DeviceName = "tester"
	m.AddConnection(conn, hello)

	if cfg.Devices()[device1].Name != "tester" {
		t.Errorf("Device did not get a name")
	}

	m.Closed(conn, protocol.ErrTimeout)
	hello.DeviceName = "tester2"
	m.AddConnection(conn, hello)

	if cfg.Devices()[device1].Name != "tester" {
		t.Errorf("Device name got overwritten")
	}

	cfgw, _, err := config.Load("testdata/tmpconfig.xml", myID, events.NoopLogger)
	if err != nil {
		t.Error(err)
		return
	}
	if cfgw.Devices()[device1].Name != "tester" {
		t.Errorf("Device name not saved in config")
	}

	m.Closed(conn, protocol.ErrTimeout)

	opts := cfg.Options()
	opts.OverwriteRemoteDevNames = true
	cfg.SetOptions(opts)

	hello.DeviceName = "tester2"
	m.AddConnection(conn, hello)

	if cfg.Devices()[device1].Name != "tester2" {
		t.Errorf("Device name not overwritten")
	}
}

func TestClusterConfig(t *testing.T) {
	cfg := config.New(device1)
	cfg.Devices = []config.DeviceConfiguration{
		{
			DeviceID:   device1,
			Introducer: true,
		},
		{
			DeviceID: device2,
		},
	}
	cfg.Folders = []config.FolderConfiguration{
		{
			ID:   "folder1",
			Path: "testdata1",
			Devices: []config.FolderDeviceConfiguration{
				{DeviceID: device1},
				{DeviceID: device2},
			},
		},
		{
			ID:     "folder2",
			Path:   "testdata2",
			Paused: true, // should still be included
			Devices: []config.FolderDeviceConfiguration{
				{DeviceID: device1},
				{DeviceID: device2},
			},
		},
		{
			ID:   "folder3",
			Path: "testdata3",
			Devices: []config.FolderDeviceConfiguration{
				{DeviceID: device1},
				// should not be included, does not include device2
			},
		},
	}

	db := db.NewLowlevel(backend.OpenMemory())

	wrapper := createTmpWrapper(cfg)
	m := newModel(wrapper, myID, "syncthing", "dev", db, nil)
	m.ServeBackground()
	defer cleanupModel(m)

	cm := m.generateClusterConfig(device2)

	if l := len(cm.Folders); l != 2 {
		t.Fatalf("Incorrect number of folders %d != 2", l)
	}

	r := cm.Folders[0]
	if r.ID != "folder1" {
		t.Errorf("Incorrect folder %q != folder1", r.ID)
	}
	if l := len(r.Devices); l != 2 {
		t.Errorf("Incorrect number of devices %d != 2", l)
	}
	if id := r.Devices[0].ID; id != device1 {
		t.Errorf("Incorrect device ID %s != %s", id, device1)
	}
	if !r.Devices[0].Introducer {
		t.Error("Device1 should be flagged as Introducer")
	}
	if id := r.Devices[1].ID; id != device2 {
		t.Errorf("Incorrect device ID %s != %s", id, device2)
	}
	if r.Devices[1].Introducer {
		t.Error("Device2 should not be flagged as Introducer")
	}

	r = cm.Folders[1]
	if r.ID != "folder2" {
		t.Errorf("Incorrect folder %q != folder2", r.ID)
	}
	if l := len(r.Devices); l != 2 {
		t.Errorf("Incorrect number of devices %d != 2", l)
	}
	if id := r.Devices[0].ID; id != device1 {
		t.Errorf("Incorrect device ID %s != %s", id, device1)
	}
	if !r.Devices[0].Introducer {
		t.Error("Device1 should be flagged as Introducer")
	}
	if id := r.Devices[1].ID; id != device2 {
		t.Errorf("Incorrect device ID %s != %s", id, device2)
	}
	if r.Devices[1].Introducer {
		t.Error("Device2 should not be flagged as Introducer")
	}
}

func TestIntroducer(t *testing.T) {
	var introducedByAnyone protocol.DeviceID

	// LocalDeviceID is a magic value meaning don't check introducer
	contains := func(cfg config.FolderConfiguration, id, introducedBy protocol.DeviceID) bool {
		for _, dev := range cfg.Devices {
			if dev.DeviceID.Equals(id) {
				if introducedBy.Equals(introducedByAnyone) {
					return true
				}
				return dev.IntroducedBy.Equals(introducedBy)
			}
		}
		return false
	}

	m := newState(config.Configuration{
		Devices: []config.DeviceConfiguration{
			{
				DeviceID:   device1,
				Introducer: true,
			},
		},
		Folders: []config.FolderConfiguration{
			{
				ID:   "folder1",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
				},
			},
			{
				ID:   "folder2",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
				},
			},
		},
	})
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID: "folder1",
				Devices: []protocol.Device{
					{
						ID:                       device2,
						Introducer:               true,
						SkipIntroductionRemovals: true,
					},
				},
			},
		},
	})

	if newDev, ok := m.cfg.Device(device2); !ok || !newDev.Introducer || !newDev.SkipIntroductionRemovals {
		t.Error("devie 2 missing or wrong flags")
	}

	if !contains(m.cfg.Folders()["folder1"], device2, device1) {
		t.Error("expected folder 1 to have device2 introduced by device 1")
	}

	cleanupModel(m)
	m = newState(config.Configuration{
		Devices: []config.DeviceConfiguration{
			{
				DeviceID:   device1,
				Introducer: true,
			},
			{
				DeviceID:     device2,
				IntroducedBy: device1,
			},
		},
		Folders: []config.FolderConfiguration{
			{
				ID:   "folder1",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
					{DeviceID: device2, IntroducedBy: device1},
				},
			},
			{
				ID:   "folder2",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
				},
			},
		},
	})
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID: "folder2",
				Devices: []protocol.Device{
					{
						ID:                       device2,
						Introducer:               true,
						SkipIntroductionRemovals: true,
					},
				},
			},
		},
	})

	// Should not get introducer, as it's already unset, and it's an existing device.
	if newDev, ok := m.cfg.Device(device2); !ok || newDev.Introducer || newDev.SkipIntroductionRemovals {
		t.Error("device 2 missing or changed flags")
	}

	if contains(m.cfg.Folders()["folder1"], device2, introducedByAnyone) {
		t.Error("expected device 2 to be removed from folder 1")
	}

	if !contains(m.cfg.Folders()["folder2"], device2, device1) {
		t.Error("expected device 2 to be added to folder 2")
	}

	cleanupModel(m)
	m = newState(config.Configuration{
		Devices: []config.DeviceConfiguration{
			{
				DeviceID:   device1,
				Introducer: true,
			},
			{
				DeviceID:     device2,
				IntroducedBy: device1,
			},
		},
		Folders: []config.FolderConfiguration{
			{
				ID:   "folder1",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
					{DeviceID: device2, IntroducedBy: device1},
				},
			},
			{
				ID:   "folder2",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
					{DeviceID: device2, IntroducedBy: device1},
				},
			},
		},
	})
	m.ClusterConfig(device1, protocol.ClusterConfig{})

	if _, ok := m.cfg.Device(device2); ok {
		t.Error("device 2 should have been removed")
	}

	if contains(m.cfg.Folders()["folder1"], device2, introducedByAnyone) {
		t.Error("expected device 2 to be removed from folder 1")
	}

	if contains(m.cfg.Folders()["folder2"], device2, introducedByAnyone) {
		t.Error("expected device 2 to be removed from folder 2")
	}

	// Two cases when removals should not happen
	// 1. Introducer flag no longer set on device

	cleanupModel(m)
	m = newState(config.Configuration{
		Devices: []config.DeviceConfiguration{
			{
				DeviceID:   device1,
				Introducer: false,
			},
			{
				DeviceID:     device2,
				IntroducedBy: device1,
			},
		},
		Folders: []config.FolderConfiguration{
			{
				ID:   "folder1",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
					{DeviceID: device2, IntroducedBy: device1},
				},
			},
			{
				ID:   "folder2",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
					{DeviceID: device2, IntroducedBy: device1},
				},
			},
		},
	})
	m.ClusterConfig(device1, protocol.ClusterConfig{})

	if _, ok := m.cfg.Device(device2); !ok {
		t.Error("device 2 should not have been removed")
	}

	if !contains(m.cfg.Folders()["folder1"], device2, device1) {
		t.Error("expected device 2 not to be removed from folder 1")
	}

	if !contains(m.cfg.Folders()["folder2"], device2, device1) {
		t.Error("expected device 2 not to be removed from folder 2")
	}

	// 2. SkipIntroductionRemovals is set

	cleanupModel(m)
	m = newState(config.Configuration{
		Devices: []config.DeviceConfiguration{
			{
				DeviceID:                 device1,
				Introducer:               true,
				SkipIntroductionRemovals: true,
			},
			{
				DeviceID:     device2,
				IntroducedBy: device1,
			},
		},
		Folders: []config.FolderConfiguration{
			{
				ID:   "folder1",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
					{DeviceID: device2, IntroducedBy: device1},
				},
			},
			{
				ID:   "folder2",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
				},
			},
		},
	})
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID: "folder2",
				Devices: []protocol.Device{
					{
						ID:                       device2,
						Introducer:               true,
						SkipIntroductionRemovals: true,
					},
				},
			},
		},
	})

	if _, ok := m.cfg.Device(device2); !ok {
		t.Error("device 2 should not have been removed")
	}

	if !contains(m.cfg.Folders()["folder1"], device2, device1) {
		t.Error("expected device 2 not to be removed from folder 1")
	}

	if !contains(m.cfg.Folders()["folder2"], device2, device1) {
		t.Error("expected device 2 not to be added to folder 2")
	}

	// Test device not being removed as it's shared without an introducer.

	cleanupModel(m)
	m = newState(config.Configuration{
		Devices: []config.DeviceConfiguration{
			{
				DeviceID:   device1,
				Introducer: true,
			},
			{
				DeviceID:     device2,
				IntroducedBy: device1,
			},
		},
		Folders: []config.FolderConfiguration{
			{
				ID:   "folder1",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
					{DeviceID: device2, IntroducedBy: device1},
				},
			},
			{
				ID:   "folder2",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
					{DeviceID: device2},
				},
			},
		},
	})
	m.ClusterConfig(device1, protocol.ClusterConfig{})

	if _, ok := m.cfg.Device(device2); !ok {
		t.Error("device 2 should not have been removed")
	}

	if contains(m.cfg.Folders()["folder1"], device2, introducedByAnyone) {
		t.Error("expected device 2 to be removed from folder 1")
	}

	if !contains(m.cfg.Folders()["folder2"], device2, introducedByAnyone) {
		t.Error("expected device 2 not to be removed from folder 2")
	}

	// Test device not being removed as it's shared by a different introducer.

	cleanupModel(m)
	m = newState(config.Configuration{
		Devices: []config.DeviceConfiguration{
			{
				DeviceID:   device1,
				Introducer: true,
			},
			{
				DeviceID:     device2,
				IntroducedBy: device1,
			},
		},
		Folders: []config.FolderConfiguration{
			{
				ID:   "folder1",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
					{DeviceID: device2, IntroducedBy: device1},
				},
			},
			{
				ID:   "folder2",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
					{DeviceID: device2, IntroducedBy: myID},
				},
			},
		},
	})
	defer cleanupModel(m)
	m.ClusterConfig(device1, protocol.ClusterConfig{})

	if _, ok := m.cfg.Device(device2); !ok {
		t.Error("device 2 should not have been removed")
	}

	if contains(m.cfg.Folders()["folder1"], device2, introducedByAnyone) {
		t.Error("expected device 2 to be removed from folder 1")
	}

	if !contains(m.cfg.Folders()["folder2"], device2, introducedByAnyone) {
		t.Error("expected device 2 not to be removed from folder 2")
	}
}

func TestIssue4897(t *testing.T) {
	m := newState(config.Configuration{
		Devices: []config.DeviceConfiguration{
			{
				DeviceID:   device1,
				Introducer: true,
			},
		},
		Folders: []config.FolderConfiguration{
			{
				ID:   "folder1",
				Path: "testdata",
				Devices: []config.FolderDeviceConfiguration{
					{DeviceID: device1},
				},
				Paused: true,
			},
		},
	})
	defer cleanupModel(m)

	cm := m.generateClusterConfig(device1)
	if l := len(cm.Folders); l != 1 {
		t.Errorf("Cluster config contains %v folders, expected 1", l)
	}
}

// TestIssue5063 is about a panic in connection with modifying config in quick
// succession, related with auto accepted folders. It's unclear what exactly, a
// relevant bit seems to be here:
// PR-comments: https://github.com/syncthing/syncthing/pull/5069/files#r203146546
// Issue: https://github.com/syncthing/syncthing/pull/5509
func TestIssue5063(t *testing.T) {
	m := newState(defaultAutoAcceptCfg)
	defer cleanupModel(m)

	m.pmut.Lock()
	for _, c := range m.conn {
		conn := c.(*fakeConnection)
		conn.mut.Lock()
		conn.closeFn = func(_ error) {}
		conn.mut.Unlock()
		defer m.Closed(c, errStopped) // to unblock deferred m.Stop()
	}
	m.pmut.Unlock()

	wg := sync.WaitGroup{}

	addAndVerify := func(id string) {
		m.ClusterConfig(device1, protocol.ClusterConfig{
			Folders: []protocol.Folder{
				{
					ID:    id,
					Label: id,
				},
			},
		})
		if fcfg, ok := m.cfg.Folder(id); !ok || !fcfg.SharedWith(device1) {
			t.Error("expected shared", id)
		}
		wg.Done()
	}

	reps := 10
	ids := make([]string, reps)
	for i := 0; i < reps; i++ {
		wg.Add(1)
		ids[i] = srand.String(8)
		go addAndVerify(ids[i])
	}
	defer func() {
		for _, id := range ids {
			os.RemoveAll(id)
		}
	}()

	finished := make(chan struct{})
	go func() {
		wg.Wait()
		close(finished)
	}()
	select {
	case <-finished:
	case <-time.After(10 * time.Second):
		pprof.Lookup("goroutine").WriteTo(os.Stdout, 1)
		t.Fatal("Timed out before all devices were added")
	}
}

func TestAutoAcceptRejected(t *testing.T) {
	// Nothing happens if AutoAcceptFolders not set
	tcfg := defaultAutoAcceptCfg.Copy()
	for i := range tcfg.Devices {
		tcfg.Devices[i].AutoAcceptFolders = false
	}
	m := newState(tcfg)
	defer cleanupModel(m)
	id := srand.String(8)
	defer os.RemoveAll(id)
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id,
				Label: id,
			},
		},
	})

	if cfg, ok := m.cfg.Folder(id); ok && cfg.SharedWith(device1) {
		t.Error("unexpected shared", id)
	}
}

func TestAutoAcceptNewFolder(t *testing.T) {
	// New folder
	m := newState(defaultAutoAcceptCfg)
	defer cleanupModel(m)
	id := srand.String(8)
	defer os.RemoveAll(id)
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id,
				Label: id,
			},
		},
	})
	if fcfg, ok := m.cfg.Folder(id); !ok || !fcfg.SharedWith(device1) {
		t.Error("expected shared", id)
	}
}

func TestAutoAcceptNewFolderFromTwoDevices(t *testing.T) {
	m := newState(defaultAutoAcceptCfg)
	defer cleanupModel(m)
	id := srand.String(8)
	defer os.RemoveAll(id)
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id,
				Label: id,
			},
		},
	})
	if fcfg, ok := m.cfg.Folder(id); !ok || !fcfg.SharedWith(device1) {
		t.Error("expected shared", id)
	}
	if fcfg, ok := m.cfg.Folder(id); !ok || fcfg.SharedWith(device2) {
		t.Error("unexpected expected shared", id)
	}
	m.ClusterConfig(device2, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id,
				Label: id,
			},
		},
	})
	if fcfg, ok := m.cfg.Folder(id); !ok || !fcfg.SharedWith(device2) {
		t.Error("expected shared", id)
	}
}

func TestAutoAcceptNewFolderFromOnlyOneDevice(t *testing.T) {
	modifiedCfg := defaultAutoAcceptCfg.Copy()
	modifiedCfg.Devices[2].AutoAcceptFolders = false
	m := newState(modifiedCfg)
	id := srand.String(8)
	defer os.RemoveAll(id)
	defer cleanupModel(m)
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id,
				Label: id,
			},
		},
	})
	if fcfg, ok := m.cfg.Folder(id); !ok || !fcfg.SharedWith(device1) {
		t.Error("expected shared", id)
	}
	if fcfg, ok := m.cfg.Folder(id); !ok || fcfg.SharedWith(device2) {
		t.Error("unexpected expected shared", id)
	}
	m.ClusterConfig(device2, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id,
				Label: id,
			},
		},
	})
	if fcfg, ok := m.cfg.Folder(id); !ok || fcfg.SharedWith(device2) {
		t.Error("unexpected shared", id)
	}
}

func TestAutoAcceptNewFolderPremutationsNoPanic(t *testing.T) {
	if testing.Short() {
		t.Skip("short tests only")
	}

	testOs := &fatalOs{t}

	id := srand.String(8)
	label := srand.String(8)
	premutations := []protocol.Folder{
		{ID: id, Label: id},
		{ID: id, Label: label},
		{ID: label, Label: id},
		{ID: label, Label: label},
	}
	localFolders := append(premutations, protocol.Folder{})
	for _, localFolder := range localFolders {
		for _, localFolderPaused := range []bool{false, true} {
			for _, dev1folder := range premutations {
				for _, dev2folder := range premutations {
					cfg := defaultAutoAcceptCfg.Copy()
					if localFolder.Label != "" {
						fcfg := config.NewFolderConfiguration(myID, localFolder.ID, localFolder.Label, fs.FilesystemTypeBasic, localFolder.ID)
						fcfg.Paused = localFolderPaused
						cfg.Folders = append(cfg.Folders, fcfg)
					}
					m := newState(cfg)
					m.ClusterConfig(device1, protocol.ClusterConfig{
						Folders: []protocol.Folder{dev1folder},
					})
					m.ClusterConfig(device2, protocol.ClusterConfig{
						Folders: []protocol.Folder{dev2folder},
					})
					cleanupModel(m)
					testOs.RemoveAll(id)
					testOs.RemoveAll(label)
				}
			}
		}
	}
}

func TestAutoAcceptMultipleFolders(t *testing.T) {
	// Multiple new folders
	id1 := srand.String(8)
	defer os.RemoveAll(id1)
	id2 := srand.String(8)
	defer os.RemoveAll(id2)
	m := newState(defaultAutoAcceptCfg)
	defer cleanupModel(m)
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id1,
				Label: id1,
			},
			{
				ID:    id2,
				Label: id2,
			},
		},
	})
	if fcfg, ok := m.cfg.Folder(id1); !ok || !fcfg.SharedWith(device1) {
		t.Error("expected shared", id1)
	}
	if fcfg, ok := m.cfg.Folder(id2); !ok || !fcfg.SharedWith(device1) {
		t.Error("expected shared", id2)
	}
}

func TestAutoAcceptExistingFolder(t *testing.T) {
	// Existing folder
	id := srand.String(8)
	idOther := srand.String(8) // To check that path does not get changed.
	defer os.RemoveAll(id)
	defer os.RemoveAll(idOther)

	tcfg := defaultAutoAcceptCfg.Copy()
	tcfg.Folders = []config.FolderConfiguration{
		{
			ID:   id,
			Path: idOther, // To check that path does not get changed.
		},
	}
	m := newState(tcfg)
	defer cleanupModel(m)
	if fcfg, ok := m.cfg.Folder(id); !ok || fcfg.SharedWith(device1) {
		t.Error("missing folder, or shared", id)
	}
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id,
				Label: id,
			},
		},
	})

	if fcfg, ok := m.cfg.Folder(id); !ok || !fcfg.SharedWith(device1) || fcfg.Path != idOther {
		t.Error("missing folder, or unshared, or path changed", id)
	}
}

func TestAutoAcceptNewAndExistingFolder(t *testing.T) {
	// New and existing folder
	id1 := srand.String(8)
	defer os.RemoveAll(id1)
	id2 := srand.String(8)
	defer os.RemoveAll(id2)

	tcfg := defaultAutoAcceptCfg.Copy()
	tcfg.Folders = []config.FolderConfiguration{
		{
			ID:   id1,
			Path: id1, // from previous test case, to verify that path doesn't get changed.
		},
	}
	m := newState(tcfg)
	defer cleanupModel(m)
	if fcfg, ok := m.cfg.Folder(id1); !ok || fcfg.SharedWith(device1) {
		t.Error("missing folder, or shared", id1)
	}
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id1,
				Label: id1,
			},
			{
				ID:    id2,
				Label: id2,
			},
		},
	})

	for i, id := range []string{id1, id2} {
		if fcfg, ok := m.cfg.Folder(id); !ok || !fcfg.SharedWith(device1) {
			t.Error("missing folder, or unshared", i, id)
		}
	}
}

func TestAutoAcceptAlreadyShared(t *testing.T) {
	// Already shared
	id := srand.String(8)
	defer os.RemoveAll(id)
	tcfg := defaultAutoAcceptCfg.Copy()
	tcfg.Folders = []config.FolderConfiguration{
		{
			ID:   id,
			Path: id,
			Devices: []config.FolderDeviceConfiguration{
				{
					DeviceID: device1,
				},
			},
		},
	}
	m := newState(tcfg)
	defer cleanupModel(m)
	if fcfg, ok := m.cfg.Folder(id); !ok || !fcfg.SharedWith(device1) {
		t.Error("missing folder, or not shared", id)
	}
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id,
				Label: id,
			},
		},
	})

	if fcfg, ok := m.cfg.Folder(id); !ok || !fcfg.SharedWith(device1) {
		t.Error("missing folder, or not shared", id)
	}
}

func TestAutoAcceptNameConflict(t *testing.T) {
	testOs := &fatalOs{t}

	id := srand.String(8)
	label := srand.String(8)
	testOs.MkdirAll(id, 0777)
	testOs.MkdirAll(label, 0777)
	defer os.RemoveAll(id)
	defer os.RemoveAll(label)
	m := newState(defaultAutoAcceptCfg)
	defer cleanupModel(m)
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id,
				Label: label,
			},
		},
	})
	if fcfg, ok := m.cfg.Folder(id); ok && fcfg.SharedWith(device1) {
		t.Error("unexpected folder", id)
	}
}

func TestAutoAcceptPrefersLabel(t *testing.T) {
	// Prefers label, falls back to ID.
	m := newState(defaultAutoAcceptCfg)
	id := srand.String(8)
	label := srand.String(8)
	defer os.RemoveAll(id)
	defer os.RemoveAll(label)
	defer cleanupModel(m)
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id,
				Label: label,
			},
		},
	})
	if fcfg, ok := m.cfg.Folder(id); !ok || !fcfg.SharedWith(device1) || !strings.HasSuffix(fcfg.Path, label) {
		t.Error("expected shared, or wrong path", id, label, fcfg.Path)
	}
}

func TestAutoAcceptFallsBackToID(t *testing.T) {
	testOs := &fatalOs{t}

	// Prefers label, falls back to ID.
	m := newState(defaultAutoAcceptCfg)
	id := srand.String(8)
	label := srand.String(8)
	t.Log(id, label)
	testOs.MkdirAll(label, 0777)
	defer os.RemoveAll(label)
	defer os.RemoveAll(id)
	defer cleanupModel(m)
	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id,
				Label: label,
			},
		},
	})
	if fcfg, ok := m.cfg.Folder(id); !ok || !fcfg.SharedWith(device1) || !strings.HasSuffix(fcfg.Path, id) {
		t.Error("expected shared, or wrong path", id, label, fcfg.Path)
	}
}

func TestAutoAcceptPausedWhenFolderConfigChanged(t *testing.T) {
	// Existing folder
	id := srand.String(8)
	idOther := srand.String(8) // To check that path does not get changed.
	defer os.RemoveAll(id)
	defer os.RemoveAll(idOther)

	tcfg := defaultAutoAcceptCfg.Copy()
	fcfg := config.NewFolderConfiguration(myID, id, "", fs.FilesystemTypeBasic, idOther)
	fcfg.Paused = true
	// The order of devices here is wrong (cfg.clean() sorts them), which will cause the folder to restart.
	// Because of the restart, folder gets removed from m.deviceFolder, which means that generateClusterConfig will not panic.
	// This wasn't an issue before, yet keeping the test case to prove that it still isn't.
	fcfg.Devices = append(fcfg.Devices, config.FolderDeviceConfiguration{
		DeviceID: device1,
	})
	tcfg.Folders = []config.FolderConfiguration{fcfg}
	m := newState(tcfg)
	defer cleanupModel(m)
	if fcfg, ok := m.cfg.Folder(id); !ok || !fcfg.SharedWith(device1) {
		t.Error("missing folder, or not shared", id)
	}
	if _, ok := m.folderRunners[id]; ok {
		t.Fatal("folder running?")
	}

	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id,
				Label: id,
			},
		},
	})
	m.generateClusterConfig(device1)

	if fcfg, ok := m.cfg.Folder(id); !ok {
		t.Error("missing folder")
	} else if fcfg.Path != idOther {
		t.Error("folder path changed")
	} else {
		for _, dev := range fcfg.DeviceIDs() {
			if dev == device1 {
				return
			}
		}
		t.Error("device missing")
	}

	if _, ok := m.folderRunners[id]; ok {
		t.Error("folder started")
	}
}

func TestAutoAcceptPausedWhenFolderConfigNotChanged(t *testing.T) {
	// Existing folder
	id := srand.String(8)
	idOther := srand.String(8) // To check that path does not get changed.
	defer os.RemoveAll(id)
	defer os.RemoveAll(idOther)

	tcfg := defaultAutoAcceptCfg.Copy()
	fcfg := config.NewFolderConfiguration(myID, id, "", fs.FilesystemTypeBasic, idOther)
	fcfg.Paused = true
	// The new folder is exactly the same as the one constructed by handleAutoAccept, which means
	// the folder will not be restarted (even if it's paused), yet handleAutoAccept used to add the folder
	// to m.deviceFolders which had caused panics when calling generateClusterConfig, as the folder
	// did not have a file set.
	fcfg.Devices = append([]config.FolderDeviceConfiguration{
		{
			DeviceID: device1,
		},
	}, fcfg.Devices...) // Need to ensure this device order to avoid folder restart.
	tcfg.Folders = []config.FolderConfiguration{fcfg}
	m := newState(tcfg)
	defer cleanupModel(m)
	if fcfg, ok := m.cfg.Folder(id); !ok || !fcfg.SharedWith(device1) {
		t.Error("missing folder, or not shared", id)
	}
	if _, ok := m.folderRunners[id]; ok {
		t.Fatal("folder running?")
	}

	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID:    id,
				Label: id,
			},
		},
	})
	m.generateClusterConfig(device1)

	if fcfg, ok := m.cfg.Folder(id); !ok {
		t.Error("missing folder")
	} else if fcfg.Path != idOther {
		t.Error("folder path changed")
	} else {
		for _, dev := range fcfg.DeviceIDs() {
			if dev == device1 {
				return
			}
		}
		t.Error("device missing")
	}

	if _, ok := m.folderRunners[id]; ok {
		t.Error("folder started")
	}
}

func changeIgnores(t *testing.T, m *model, expected []string) {
	arrEqual := func(a, b []string) bool {
		if len(a) != len(b) {
			return false
		}

		for i := range a {
			if a[i] != b[i] {
				return false
			}
		}
		return true
	}

	ignores, _, err := m.GetIgnores("default")
	if err != nil {
		t.Error(err)
	}

	if !arrEqual(ignores, expected) {
		t.Errorf("Incorrect ignores: %v != %v", ignores, expected)
	}

	ignores = append(ignores, "pox")

	err = m.SetIgnores("default", ignores)
	if err != nil {
		t.Error(err)
	}

	ignores2, _, err := m.GetIgnores("default")
	if err != nil {
		t.Error(err)
	}

	if !arrEqual(ignores, ignores2) {
		t.Errorf("Incorrect ignores: %v != %v", ignores2, ignores)
	}

	if runtime.GOOS == "darwin" {
		// see above
		time.Sleep(time.Second)
	} else {
		time.Sleep(time.Millisecond)
	}
	err = m.SetIgnores("default", expected)
	if err != nil {
		t.Error(err)
	}

	ignores, _, err = m.GetIgnores("default")
	if err != nil {
		t.Error(err)
	}

	if !arrEqual(ignores, expected) {
		t.Errorf("Incorrect ignores: %v != %v", ignores, expected)
	}
}

func TestIgnores(t *testing.T) {
	// Assure a clean start state
	mustRemove(t, defaultFs.RemoveAll(config.DefaultMarkerName))
	mustRemove(t, defaultFs.MkdirAll(config.DefaultMarkerName, 0644))
	writeFile(defaultFs, ".stignore", []byte(".*\nquux\n"), 0644)

	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	folderIgnoresAlwaysReload(m, defaultFolderConfig)

	// Make sure the initial scan has finished (ScanFolders is blocking)
	m.ScanFolders()

	expected := []string{
		".*",
		"quux",
	}

	changeIgnores(t, m, expected)

	_, _, err := m.GetIgnores("doesnotexist")
	if err == nil {
		t.Error("No error")
	}

	err = m.SetIgnores("doesnotexist", expected)
	if err == nil {
		t.Error("No error")
	}

	// Invalid path, marker should be missing, hence returns an error.
	fcfg := config.FolderConfiguration{ID: "fresh", Path: "XXX"}
	ignores := ignore.New(fcfg.Filesystem(), ignore.WithCache(m.cfg.Options().CacheIgnoredFiles))
	m.fmut.Lock()
	m.folderCfgs[fcfg.ID] = fcfg
	m.folderIgnores[fcfg.ID] = ignores
	m.fmut.Unlock()

	_, _, err = m.GetIgnores("fresh")
	if err == nil {
		t.Error("No error")
	}

	// Repeat tests with paused folder
	pausedDefaultFolderConfig := defaultFolderConfig
	pausedDefaultFolderConfig.Paused = true

	m.restartFolder(defaultFolderConfig, pausedDefaultFolderConfig, false)
	// Here folder initialization is not an issue as a paused folder isn't
	// added to the model and thus there is no initial scan happening.

	changeIgnores(t, m, expected)

	// Make sure no .stignore file is considered valid
	defer func() {
		must(t, defaultFs.Rename(".stignore.bak", ".stignore"))
	}()
	must(t, defaultFs.Rename(".stignore", ".stignore.bak"))
	changeIgnores(t, m, []string{})
}

func TestEmptyIgnores(t *testing.T) {
	// Assure a clean start state
	mustRemove(t, defaultFs.RemoveAll(config.DefaultMarkerName))
	must(t, defaultFs.MkdirAll(config.DefaultMarkerName, 0644))

	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	if err := m.SetIgnores("default", []string{}); err != nil {
		t.Error(err)
	}
	if _, err := os.Stat("testdata/.stignore"); err == nil {
		t.Error(".stignore was created despite being empty")
	}

	if err := m.SetIgnores("default", []string{".*", "quux"}); err != nil {
		t.Error(err)
	}
	if _, err := os.Stat("testdata/.stignore"); os.IsNotExist(err) {
		t.Error(".stignore does not exist")
	}

	if err := m.SetIgnores("default", []string{}); err != nil {
		t.Error(err)
	}
	if _, err := os.Stat("testdata/.stignore"); err == nil {
		t.Error(".stignore should have been deleted because it is empty")
	}
}

func waitForState(t *testing.T, sub events.Subscription, folder, expected string) {
	t.Helper()
	timeout := time.After(5 * time.Second)
	var error string
	for {
		select {
		case ev := <-sub.C():
			data := ev.Data.(map[string]interface{})
			if data["folder"].(string) == folder {
				if data["error"] == nil {
					error = ""
				} else {
					error = data["error"].(string)
				}
				if error == expected {
					return
				}
			}
		case <-timeout:
			t.Fatalf("Timed out waiting for status: %s, current status: %v", expected, error)
		}
	}
}

func TestROScanRecovery(t *testing.T) {
	testOs := &fatalOs{t}

	ldb := db.NewLowlevel(backend.OpenMemory())
	set := db.NewFileSet("default", defaultFs, ldb)
	set.Update(protocol.LocalDeviceID, []protocol.FileInfo{
		{Name: "dummyfile", Version: protocol.Vector{Counters: []protocol.Counter{{ID: 42, Value: 1}}}},
	})

	fcfg := config.FolderConfiguration{
		ID:              "default",
		Path:            "rotestfolder",
		Type:            config.FolderTypeSendOnly,
		RescanIntervalS: 1,
		MarkerName:      config.DefaultMarkerName,
	}
	cfg := createTmpWrapper(config.Configuration{
		Folders: []config.FolderConfiguration{fcfg},
		Devices: []config.DeviceConfiguration{
			{
				DeviceID: device1,
			},
		},
	})

	testOs.RemoveAll(fcfg.Path)

	m := newModel(cfg, myID, "syncthing", "dev", ldb, nil)
	sub := m.evLogger.Subscribe(events.StateChanged)
	defer sub.Unsubscribe()
	m.ServeBackground()
	defer cleanupModel(m)

	waitForState(t, sub, "default", "folder path missing")

	testOs.Mkdir(fcfg.Path, 0700)

	waitForState(t, sub, "default", config.ErrMarkerMissing.Error())

	fd := testOs.Create(filepath.Join(fcfg.Path, config.DefaultMarkerName))
	fd.Close()

	waitForState(t, sub, "default", "")

	testOs.Remove(filepath.Join(fcfg.Path, config.DefaultMarkerName))

	waitForState(t, sub, "default", config.ErrMarkerMissing.Error())

	testOs.Remove(fcfg.Path)

	waitForState(t, sub, "default", "folder path missing")
}

func TestRWScanRecovery(t *testing.T) {
	testOs := &fatalOs{t}

	ldb := db.NewLowlevel(backend.OpenMemory())
	set := db.NewFileSet("default", defaultFs, ldb)
	set.Update(protocol.LocalDeviceID, []protocol.FileInfo{
		{Name: "dummyfile", Version: protocol.Vector{Counters: []protocol.Counter{{ID: 42, Value: 1}}}},
	})

	fcfg := config.FolderConfiguration{
		ID:              "default",
		Path:            "rwtestfolder",
		Type:            config.FolderTypeSendReceive,
		RescanIntervalS: 1,
		MarkerName:      config.DefaultMarkerName,
	}
	cfg := createTmpWrapper(config.Configuration{
		Folders: []config.FolderConfiguration{fcfg},
		Devices: []config.DeviceConfiguration{
			{
				DeviceID: device1,
			},
		},
	})

	testOs.RemoveAll(fcfg.Path)

	m := newModel(cfg, myID, "syncthing", "dev", ldb, nil)
	sub := m.evLogger.Subscribe(events.StateChanged)
	defer sub.Unsubscribe()
	m.ServeBackground()
	defer cleanupModel(m)

	waitForState(t, sub, "default", "folder path missing")

	testOs.Mkdir(fcfg.Path, 0700)

	waitForState(t, sub, "default", config.ErrMarkerMissing.Error())

	fd := testOs.Create(filepath.Join(fcfg.Path, config.DefaultMarkerName))
	fd.Close()

	waitForState(t, sub, "default", "")

	testOs.Remove(filepath.Join(fcfg.Path, config.DefaultMarkerName))

	waitForState(t, sub, "default", config.ErrMarkerMissing.Error())

	testOs.Remove(fcfg.Path)

	waitForState(t, sub, "default", "folder path missing")
}

func TestGlobalDirectoryTree(t *testing.T) {
	db := db.NewLowlevel(backend.OpenMemory())
	m := newModel(defaultCfgWrapper, myID, "syncthing", "dev", db, nil)
	m.ServeBackground()
	defer cleanupModel(m)

	b := func(isfile bool, path ...string) protocol.FileInfo {
		typ := protocol.FileInfoTypeDirectory
		blocks := []protocol.BlockInfo{}
		if isfile {
			typ = protocol.FileInfoTypeFile
			blocks = []protocol.BlockInfo{{Offset: 0x0, Size: 0xa, Hash: []uint8{0x2f, 0x72, 0xcc, 0x11, 0xa6, 0xfc, 0xd0, 0x27, 0x1e, 0xce, 0xf8, 0xc6, 0x10, 0x56, 0xee, 0x1e, 0xb1, 0x24, 0x3b, 0xe3, 0x80, 0x5b, 0xf9, 0xa9, 0xdf, 0x98, 0xf9, 0x2f, 0x76, 0x36, 0xb0, 0x5c}}}
		}
		return protocol.FileInfo{
			Name:      filepath.Join(path...),
			Type:      typ,
			ModifiedS: 0x666,
			Blocks:    blocks,
			Size:      0xa,
		}
	}

	filedata := []interface{}{time.Unix(0x666, 0), 0xa}

	testdata := []protocol.FileInfo{
		b(false, "another"),
		b(false, "another", "directory"),
		b(true, "another", "directory", "afile"),
		b(false, "another", "directory", "with"),
		b(false, "another", "directory", "with", "a"),
		b(true, "another", "directory", "with", "a", "file"),
		b(true, "another", "directory", "with", "file"),
		b(true, "another", "file"),

		b(false, "other"),
		b(false, "other", "rand"),
		b(false, "other", "random"),
		b(false, "other", "random", "dir"),
		b(false, "other", "random", "dirx"),
		b(false, "other", "randomx"),

		b(false, "some"),
		b(false, "some", "directory"),
		b(false, "some", "directory", "with"),
		b(false, "some", "directory", "with", "a"),
		b(true, "some", "directory", "with", "a", "file"),

		b(true, "rootfile"),
	}
	expectedResult := map[string]interface{}{
		"another": map[string]interface{}{
			"directory": map[string]interface{}{
				"afile": filedata,
				"with": map[string]interface{}{
					"a": map[string]interface{}{
						"file": filedata,
					},
					"file": filedata,
				},
			},
			"file": filedata,
		},
		"other": map[string]interface{}{
			"rand": map[string]interface{}{},
			"random": map[string]interface{}{
				"dir":  map[string]interface{}{},
				"dirx": map[string]interface{}{},
			},
			"randomx": map[string]interface{}{},
		},
		"some": map[string]interface{}{
			"directory": map[string]interface{}{
				"with": map[string]interface{}{
					"a": map[string]interface{}{
						"file": filedata,
					},
				},
			},
		},
		"rootfile": filedata,
	}

	mm := func(data interface{}) string {
		bytes, err := json.Marshal(data)
		if err != nil {
			panic(err)
		}
		return string(bytes)
	}

	m.Index(device1, "default", testdata)

	result := m.GlobalDirectoryTree("default", "", -1, false)

	if mm(result) != mm(expectedResult) {
		t.Errorf("Does not match:\n%#v\n%#v", result, expectedResult)
	}

	result = m.GlobalDirectoryTree("default", "another", -1, false)

	if mm(result) != mm(expectedResult["another"]) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(expectedResult["another"]))
	}

	result = m.GlobalDirectoryTree("default", "", 0, false)
	currentResult := map[string]interface{}{
		"another":  map[string]interface{}{},
		"other":    map[string]interface{}{},
		"some":     map[string]interface{}{},
		"rootfile": filedata,
	}

	if mm(result) != mm(currentResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(currentResult))
	}

	result = m.GlobalDirectoryTree("default", "", 1, false)
	currentResult = map[string]interface{}{
		"another": map[string]interface{}{
			"directory": map[string]interface{}{},
			"file":      filedata,
		},
		"other": map[string]interface{}{
			"rand":    map[string]interface{}{},
			"random":  map[string]interface{}{},
			"randomx": map[string]interface{}{},
		},
		"some": map[string]interface{}{
			"directory": map[string]interface{}{},
		},
		"rootfile": filedata,
	}

	if mm(result) != mm(currentResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(currentResult))
	}

	result = m.GlobalDirectoryTree("default", "", -1, true)
	currentResult = map[string]interface{}{
		"another": map[string]interface{}{
			"directory": map[string]interface{}{
				"with": map[string]interface{}{
					"a": map[string]interface{}{},
				},
			},
		},
		"other": map[string]interface{}{
			"rand": map[string]interface{}{},
			"random": map[string]interface{}{
				"dir":  map[string]interface{}{},
				"dirx": map[string]interface{}{},
			},
			"randomx": map[string]interface{}{},
		},
		"some": map[string]interface{}{
			"directory": map[string]interface{}{
				"with": map[string]interface{}{
					"a": map[string]interface{}{},
				},
			},
		},
	}

	if mm(result) != mm(currentResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(currentResult))
	}

	result = m.GlobalDirectoryTree("default", "", 1, true)
	currentResult = map[string]interface{}{
		"another": map[string]interface{}{
			"directory": map[string]interface{}{},
		},
		"other": map[string]interface{}{
			"rand":    map[string]interface{}{},
			"random":  map[string]interface{}{},
			"randomx": map[string]interface{}{},
		},
		"some": map[string]interface{}{
			"directory": map[string]interface{}{},
		},
	}

	if mm(result) != mm(currentResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(currentResult))
	}

	result = m.GlobalDirectoryTree("default", "another", 0, false)
	currentResult = map[string]interface{}{
		"directory": map[string]interface{}{},
		"file":      filedata,
	}

	if mm(result) != mm(currentResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(currentResult))
	}

	result = m.GlobalDirectoryTree("default", "some/directory", 0, false)
	currentResult = map[string]interface{}{
		"with": map[string]interface{}{},
	}

	if mm(result) != mm(currentResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(currentResult))
	}

	result = m.GlobalDirectoryTree("default", "some/directory", 1, false)
	currentResult = map[string]interface{}{
		"with": map[string]interface{}{
			"a": map[string]interface{}{},
		},
	}

	if mm(result) != mm(currentResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(currentResult))
	}

	result = m.GlobalDirectoryTree("default", "some/directory", 2, false)
	currentResult = map[string]interface{}{
		"with": map[string]interface{}{
			"a": map[string]interface{}{
				"file": filedata,
			},
		},
	}

	if mm(result) != mm(currentResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(currentResult))
	}

	result = m.GlobalDirectoryTree("default", "another", -1, true)
	currentResult = map[string]interface{}{
		"directory": map[string]interface{}{
			"with": map[string]interface{}{
				"a": map[string]interface{}{},
			},
		},
	}

	if mm(result) != mm(currentResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(currentResult))
	}

	// No prefix matching!
	result = m.GlobalDirectoryTree("default", "som", -1, false)
	currentResult = map[string]interface{}{}

	if mm(result) != mm(currentResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(currentResult))
	}
}

func TestGlobalDirectorySelfFixing(t *testing.T) {
	db := db.NewLowlevel(backend.OpenMemory())
	m := newModel(defaultCfgWrapper, myID, "syncthing", "dev", db, nil)
	m.ServeBackground()
	defer cleanupModel(m)

	b := func(isfile bool, path ...string) protocol.FileInfo {
		typ := protocol.FileInfoTypeDirectory
		blocks := []protocol.BlockInfo{}
		if isfile {
			typ = protocol.FileInfoTypeFile
			blocks = []protocol.BlockInfo{{Offset: 0x0, Size: 0xa, Hash: []uint8{0x2f, 0x72, 0xcc, 0x11, 0xa6, 0xfc, 0xd0, 0x27, 0x1e, 0xce, 0xf8, 0xc6, 0x10, 0x56, 0xee, 0x1e, 0xb1, 0x24, 0x3b, 0xe3, 0x80, 0x5b, 0xf9, 0xa9, 0xdf, 0x98, 0xf9, 0x2f, 0x76, 0x36, 0xb0, 0x5c}}}
		}
		return protocol.FileInfo{
			Name:      filepath.Join(path...),
			Type:      typ,
			ModifiedS: 0x666,
			Blocks:    blocks,
			Size:      0xa,
		}
	}

	filedata := []interface{}{time.Unix(0x666, 0).Format(time.RFC3339), 0xa}

	testdata := []protocol.FileInfo{
		b(true, "another", "directory", "afile"),
		b(true, "another", "directory", "with", "a", "file"),
		b(true, "another", "directory", "with", "file"),

		b(false, "other", "random", "dirx"),
		b(false, "other", "randomx"),

		b(false, "some", "directory", "with", "x"),
		b(true, "some", "directory", "with", "a", "file"),

		b(false, "this", "is", "a", "deep", "invalid", "directory"),

		b(true, "xthis", "is", "a", "deep", "invalid", "file"),
	}
	expectedResult := map[string]interface{}{
		"another": map[string]interface{}{
			"directory": map[string]interface{}{
				"afile": filedata,
				"with": map[string]interface{}{
					"a": map[string]interface{}{
						"file": filedata,
					},
					"file": filedata,
				},
			},
		},
		"other": map[string]interface{}{
			"random": map[string]interface{}{
				"dirx": map[string]interface{}{},
			},
			"randomx": map[string]interface{}{},
		},
		"some": map[string]interface{}{
			"directory": map[string]interface{}{
				"with": map[string]interface{}{
					"a": map[string]interface{}{
						"file": filedata,
					},
					"x": map[string]interface{}{},
				},
			},
		},
		"this": map[string]interface{}{
			"is": map[string]interface{}{
				"a": map[string]interface{}{
					"deep": map[string]interface{}{
						"invalid": map[string]interface{}{
							"directory": map[string]interface{}{},
						},
					},
				},
			},
		},
		"xthis": map[string]interface{}{
			"is": map[string]interface{}{
				"a": map[string]interface{}{
					"deep": map[string]interface{}{
						"invalid": map[string]interface{}{
							"file": filedata,
						},
					},
				},
			},
		},
	}

	mm := func(data interface{}) string {
		bytes, err := json.Marshal(data)
		if err != nil {
			panic(err)
		}
		return string(bytes)
	}

	m.Index(device1, "default", testdata)

	result := m.GlobalDirectoryTree("default", "", -1, false)

	if mm(result) != mm(expectedResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(expectedResult))
	}

	result = m.GlobalDirectoryTree("default", "xthis/is/a/deep", -1, false)
	currentResult := map[string]interface{}{
		"invalid": map[string]interface{}{
			"file": filedata,
		},
	}

	if mm(result) != mm(currentResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(currentResult))
	}

	result = m.GlobalDirectoryTree("default", "xthis/is/a/deep", -1, true)
	currentResult = map[string]interface{}{
		"invalid": map[string]interface{}{},
	}

	if mm(result) != mm(currentResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(currentResult))
	}

	// !!! This is actually BAD, because we don't have enough level allowance
	// to accept this file, hence the tree is left unbuilt !!!
	result = m.GlobalDirectoryTree("default", "xthis", 1, false)
	currentResult = map[string]interface{}{}

	if mm(result) != mm(currentResult) {
		t.Errorf("Does not match:\n%s\n%s", mm(result), mm(currentResult))
	}
}

func genDeepFiles(n, d int) []protocol.FileInfo {
	rand.Seed(int64(n))
	files := make([]protocol.FileInfo, n)
	t := time.Now().Unix()
	for i := 0; i < n; i++ {
		path := ""
		for i := 0; i <= d; i++ {
			path = filepath.Join(path, strconv.Itoa(rand.Int()))
		}

		sofar := ""
		for _, path := range filepath.SplitList(path) {
			sofar = filepath.Join(sofar, path)
			files[i] = protocol.FileInfo{
				Name: sofar,
			}
			i++
		}

		files[i].ModifiedS = t
		files[i].Blocks = []protocol.BlockInfo{{Offset: 0, Size: 100, Hash: []byte("some hash bytes")}}
	}

	return files
}

func BenchmarkTree_10000_50(b *testing.B) {
	benchmarkTree(b, 10000, 50)
}

func BenchmarkTree_100_50(b *testing.B) {
	benchmarkTree(b, 100, 50)
}

func BenchmarkTree_100_10(b *testing.B) {
	benchmarkTree(b, 100, 10)
}

func benchmarkTree(b *testing.B, n1, n2 int) {
	db := db.NewLowlevel(backend.OpenMemory())
	m := newModel(defaultCfgWrapper, myID, "syncthing", "dev", db, nil)
	m.ServeBackground()
	defer cleanupModel(m)

	m.ScanFolder("default")
	files := genDeepFiles(n1, n2)

	m.Index(device1, "default", files)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		m.GlobalDirectoryTree("default", "", -1, false)
	}
	b.ReportAllocs()
}

func TestIssue3028(t *testing.T) {
	// Create two files that we'll delete, one with a name that is a prefix of the other.

	must(t, writeFile(defaultFs, "testrm", []byte("Hello"), 0644))
	must(t, writeFile(defaultFs, "testrm2", []byte("Hello"), 0644))
	defer func() {
		mustRemove(t, defaultFs.Remove("testrm"))
		mustRemove(t, defaultFs.Remove("testrm2"))
	}()

	// Create a model and default folder

	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	// Get a count of how many files are there now

	locorigfiles := localSize(t, m, "default").Files
	globorigfiles := globalSize(t, m, "default").Files

	// Delete and rescan specifically these two

	must(t, defaultFs.Remove("testrm"))
	must(t, defaultFs.Remove("testrm2"))
	m.ScanFolderSubdirs("default", []string{"testrm", "testrm2"})

	// Verify that the number of files decreased by two and the number of
	// deleted files increases by two

	loc := localSize(t, m, "default")
	glob := globalSize(t, m, "default")
	if loc.Files != locorigfiles-2 {
		t.Errorf("Incorrect local accounting; got %d current files, expected %d", loc.Files, locorigfiles-2)
	}
	if glob.Files != globorigfiles-2 {
		t.Errorf("Incorrect global accounting; got %d current files, expected %d", glob.Files, globorigfiles-2)
	}
	if loc.Deleted != 2 {
		t.Errorf("Incorrect local accounting; got %d deleted files, expected 2", loc.Deleted)
	}
	if glob.Deleted != 2 {
		t.Errorf("Incorrect global accounting; got %d deleted files, expected 2", glob.Deleted)
	}
}

func TestIssue4357(t *testing.T) {
	db := db.NewLowlevel(backend.OpenMemory())
	cfg := defaultCfgWrapper.RawCopy()
	// Create a separate wrapper not to pollute other tests.
	wrapper := createTmpWrapper(config.Configuration{})
	m := newModel(wrapper, myID, "syncthing", "dev", db, nil)
	m.ServeBackground()
	defer cleanupModel(m)

	// Force the model to wire itself and add the folders
	p, err := wrapper.Replace(cfg)
	p.Wait()
	if err != nil {
		t.Error(err)
	}

	if _, ok := m.folderCfgs["default"]; !ok {
		t.Error("Folder should be running")
	}

	newCfg := wrapper.RawCopy()
	newCfg.Folders[0].Paused = true

	p, err = wrapper.Replace(newCfg)
	p.Wait()
	if err != nil {
		t.Error(err)
	}

	if _, ok := m.folderCfgs["default"]; ok {
		t.Error("Folder should not be running")
	}

	if _, ok := m.cfg.Folder("default"); !ok {
		t.Error("should still have folder in config")
	}

	p, err = wrapper.Replace(config.Configuration{})
	p.Wait()
	if err != nil {
		t.Error(err)
	}

	if _, ok := m.cfg.Folder("default"); ok {
		t.Error("should not have folder in config")
	}

	// Add the folder back, should be running
	p, err = wrapper.Replace(cfg)
	p.Wait()
	if err != nil {
		t.Error(err)
	}

	if _, ok := m.folderCfgs["default"]; !ok {
		t.Error("Folder should be running")
	}
	if _, ok := m.cfg.Folder("default"); !ok {
		t.Error("should still have folder in config")
	}

	// Should not panic when removing a running folder.
	p, err = wrapper.Replace(config.Configuration{})
	p.Wait()
	if err != nil {
		t.Error(err)
	}

	if _, ok := m.folderCfgs["default"]; ok {
		t.Error("Folder should not be running")
	}
	if _, ok := m.cfg.Folder("default"); ok {
		t.Error("should not have folder in config")
	}
}

func TestIssue2782(t *testing.T) {
	// CheckHealth should accept a symlinked folder, when using tilde-expanded path.

	if runtime.GOOS == "windows" {
		t.Skip("not reliable on Windows")
		return
	}
	home := os.Getenv("HOME")
	if home == "" {
		t.Skip("no home")
	}

	// Create the test env. Needs to be based on $HOME as tilde expansion is
	// part of the issue. Skip the test if any of this fails, as we are a
	// bit outside of our stated domain here...

	testName := ".syncthing-test." + srand.String(16)
	testDir := filepath.Join(home, testName)
	if err := os.RemoveAll(testDir); err != nil {
		t.Skip(err)
	}
	if err := os.MkdirAll(testDir+"/syncdir", 0755); err != nil {
		t.Skip(err)
	}
	if err := ioutil.WriteFile(testDir+"/syncdir/file", []byte("hello, world\n"), 0644); err != nil {
		t.Skip(err)
	}
	if err := os.Symlink("syncdir", testDir+"/synclink"); err != nil {
		t.Skip(err)
	}
	defer os.RemoveAll(testDir)

	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	if err := m.ScanFolder("default"); err != nil {
		t.Error("scan error:", err)
	}

	m.fmut.Lock()
	runner := m.folderRunners["default"]
	m.fmut.Unlock()
	if _, _, err := runner.getState(); err != nil {
		t.Error("folder error:", err)
	}
}

func TestIndexesForUnknownDevicesDropped(t *testing.T) {
	dbi := db.NewLowlevel(backend.OpenMemory())

	files := db.NewFileSet("default", defaultFs, dbi)
	files.Drop(device1)
	files.Update(device1, genFiles(1))
	files.Drop(device2)
	files.Update(device2, genFiles(1))

	if len(files.ListDevices()) != 2 {
		t.Error("expected two devices")
	}

	m := newModel(defaultCfgWrapper, myID, "syncthing", "dev", dbi, nil)
	m.newFolder(defaultFolderConfig, false)
	defer cleanupModel(m)

	// Remote sequence is cached, hence need to recreated.
	files = db.NewFileSet("default", defaultFs, dbi)

	if l := len(files.ListDevices()); l != 1 {
		t.Errorf("Expected one device got %v", l)
	}
}

func TestSharedWithClearedOnDisconnect(t *testing.T) {
	wcfg := createTmpWrapper(defaultCfg)
	wcfg.SetDevice(config.NewDeviceConfiguration(device2, "device2"))
	fcfg := wcfg.FolderList()[0]
	fcfg.Devices = append(fcfg.Devices, config.FolderDeviceConfiguration{DeviceID: device2})
	wcfg.SetFolder(fcfg)
	defer os.Remove(wcfg.ConfigPath())

	m := setupModel(wcfg)
	defer cleanupModel(m)

	conn1 := &fakeConnection{id: device1, model: m}
	m.AddConnection(conn1, protocol.HelloResult{})
	conn2 := &fakeConnection{id: device2, model: m}
	m.AddConnection(conn2, protocol.HelloResult{})

	m.ClusterConfig(device1, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID: "default",
				Devices: []protocol.Device{
					{ID: myID},
					{ID: device1},
					{ID: device2},
				},
			},
		},
	})
	m.ClusterConfig(device2, protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID: "default",
				Devices: []protocol.Device{
					{ID: myID},
					{ID: device1},
					{ID: device2},
				},
			},
		},
	})

	if fcfg, ok := m.cfg.Folder("default"); !ok || !fcfg.SharedWith(device1) {
		t.Error("not shared with device1")
	}
	if fcfg, ok := m.cfg.Folder("default"); !ok || !fcfg.SharedWith(device2) {
		t.Error("not shared with device2")
	}

	if conn2.Closed() {
		t.Error("conn already closed")
	}

	if _, err := wcfg.RemoveDevice(device2); err != nil {
		t.Error(err)
	}

	time.Sleep(100 * time.Millisecond) // Committer notification happens in a separate routine

	fcfg, ok := m.cfg.Folder("default")
	if !ok {
		t.Fatal("default folder missing")
	}
	if !fcfg.SharedWith(device1) {
		t.Error("not shared with device1")
	}
	if fcfg.SharedWith(device2) {
		t.Error("shared with device2")
	}
	for _, dev := range fcfg.Devices {
		if dev.DeviceID == device2 {
			t.Error("still there")
		}
	}

	if !conn2.Closed() {
		t.Error("connection not closed")
	}

	if _, ok := wcfg.Devices()[device2]; ok {
		t.Error("device still in config")
	}

	if _, ok := m.conn[device2]; ok {
		t.Error("conn not missing")
	}

	if _, ok := m.helloMessages[device2]; ok {
		t.Error("hello not missing")
	}

	if _, ok := m.deviceDownloads[device2]; ok {
		t.Error("downloads not missing")
	}
}

func TestIssue3496(t *testing.T) {
	t.Skip("This test deletes files that the other test depend on. Needs fixing.")

	// It seems like lots of deleted files can cause negative completion
	// percentages. Lets make sure that doesn't happen. Also do some general
	// checks on the completion calculation stuff.

	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	m.ScanFolder("default")

	addFakeConn(m, device1)
	addFakeConn(m, device2)

	// Reach into the model and grab the current file list...

	m.fmut.RLock()
	fs := m.folderFiles["default"]
	m.fmut.RUnlock()
	var localFiles []protocol.FileInfo
	snap := fs.Snapshot()
	snap.WithHave(protocol.LocalDeviceID, func(i protocol.FileIntf) bool {
		localFiles = append(localFiles, i.(protocol.FileInfo))
		return true
	})
	snap.Release()

	// Mark all files as deleted and fake it as update from device1

	for i := range localFiles {
		localFiles[i].Deleted = true
		localFiles[i].Version = localFiles[i].Version.Update(device1.Short())
		localFiles[i].Blocks = nil
	}

	// Also add a small file that we're supposed to need, or the global size
	// stuff will bail out early due to the entire folder being zero size.

	localFiles = append(localFiles, protocol.FileInfo{
		Name:    "fake",
		Size:    1234,
		Type:    protocol.FileInfoTypeFile,
		Version: protocol.Vector{Counters: []protocol.Counter{{ID: device1.Short(), Value: 42}}},
	})

	m.IndexUpdate(device1, "default", localFiles)

	// Check that the completion percentage for us makes sense

	comp := m.Completion(protocol.LocalDeviceID, "default")
	if comp.NeedBytes > comp.GlobalBytes {
		t.Errorf("Need more bytes than exist, not possible: %d > %d", comp.NeedBytes, comp.GlobalBytes)
	}
	if comp.CompletionPct < 0 {
		t.Errorf("Less than zero percent complete, not possible: %.02f%%", comp.CompletionPct)
	}
	if comp.NeedBytes == 0 {
		t.Error("Need no bytes even though some files are deleted")
	}
	if comp.CompletionPct == 100 {
		t.Errorf("Fully complete, not possible: %.02f%%", comp.CompletionPct)
	}
	t.Log(comp)

	// Check that NeedSize does the correct thing
	need := needSize(t, m, "default")
	if need.Files != 1 || need.Bytes != 1234 {
		// The one we added synthetically above
		t.Errorf("Incorrect need size; %d, %d != 1, 1234", need.Files, need.Bytes)
	}
	if int(need.Deleted) != len(localFiles)-1 {
		// The rest
		t.Errorf("Incorrect need deletes; %d != %d", need.Deleted, len(localFiles)-1)
	}
}

func TestIssue3804(t *testing.T) {
	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	// Subdirs ending in slash should be accepted

	if err := m.ScanFolderSubdirs("default", []string{"baz/", "foo"}); err != nil {
		t.Error("Unexpected error:", err)
	}
}

func TestIssue3829(t *testing.T) {
	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	// Empty subdirs should be accepted

	if err := m.ScanFolderSubdirs("default", []string{""}); err != nil {
		t.Error("Unexpected error:", err)
	}
}

func TestNoRequestsFromPausedDevices(t *testing.T) {
	t.Skip("broken, fails randomly, #3843")

	wcfg := createTmpWrapper(defaultCfg)
	wcfg.SetDevice(config.NewDeviceConfiguration(device2, "device2"))
	fcfg := wcfg.FolderList()[0]
	fcfg.Devices = append(fcfg.Devices, config.FolderDeviceConfiguration{DeviceID: device2})
	wcfg.SetFolder(fcfg)

	m := setupModel(wcfg)
	defer cleanupModel(m)

	file := testDataExpected["foo"]
	files := m.folderFiles["default"]
	files.Update(device1, []protocol.FileInfo{file})
	files.Update(device2, []protocol.FileInfo{file})

	avail := m.Availability("default", file, file.Blocks[0])
	if len(avail) != 0 {
		t.Errorf("should not be available, no connections")
	}

	addFakeConn(m, device1)
	addFakeConn(m, device2)

	// !!! This is not what I'd expect to happen, as we don't even know if the peer has the original index !!!

	avail = m.Availability("default", file, file.Blocks[0])
	if len(avail) != 2 {
		t.Errorf("should have two available")
	}

	cc := protocol.ClusterConfig{
		Folders: []protocol.Folder{
			{
				ID: "default",
				Devices: []protocol.Device{
					{ID: device1},
					{ID: device2},
				},
			},
		},
	}

	m.ClusterConfig(device1, cc)
	m.ClusterConfig(device2, cc)

	avail = m.Availability("default", file, file.Blocks[0])
	if len(avail) != 2 {
		t.Errorf("should have two available")
	}

	m.Closed(&fakeConnection{id: device1, model: m}, errDeviceUnknown)
	m.Closed(&fakeConnection{id: device2, model: m}, errDeviceUnknown)

	avail = m.Availability("default", file, file.Blocks[0])
	if len(avail) != 0 {
		t.Errorf("should have no available")
	}

	// Test that remote paused folders are not used.

	addFakeConn(m, device1)
	addFakeConn(m, device2)

	m.ClusterConfig(device1, cc)
	ccp := cc
	ccp.Folders[0].Paused = true
	m.ClusterConfig(device1, ccp)

	avail = m.Availability("default", file, file.Blocks[0])
	if len(avail) != 1 {
		t.Errorf("should have one available")
	}
}

// TestIssue2571 tests replacing a directory with content with a symlink
func TestIssue2571(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("Scanning symlinks isn't supported on windows")
	}

	w, fcfg := tmpDefaultWrapper()
	testFs := fcfg.Filesystem()
	defer os.RemoveAll(testFs.URI())

	for _, dir := range []string{"toLink", "linkTarget"} {
		must(t, testFs.MkdirAll(dir, 0775))
		fd, err := testFs.Create(filepath.Join(dir, "a"))
		must(t, err)
		fd.Close()
	}

	m := setupModel(w)
	defer cleanupModel(m)

	must(t, testFs.RemoveAll("toLink"))

	must(t, fs.DebugSymlinkForTestsOnly(testFs, testFs, "linkTarget", "toLink"))

	m.ScanFolder("default")

	if dir, ok := m.CurrentFolderFile("default", "toLink"); !ok {
		t.Fatalf("Dir missing in db")
	} else if !dir.IsSymlink() {
		t.Errorf("Dir wasn't changed to symlink")
	}
	if file, ok := m.CurrentFolderFile("default", filepath.Join("toLink", "a")); !ok {
		t.Fatalf("File missing in db")
	} else if !file.Deleted {
		t.Errorf("File below symlink has not been marked as deleted")
	}
}

// TestIssue4573 tests that contents of an unavailable dir aren't marked deleted
func TestIssue4573(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("Can't make the dir inaccessible on windows")
	}

	w, fcfg := tmpDefaultWrapper()
	testFs := fcfg.Filesystem()
	defer os.RemoveAll(testFs.URI())

	must(t, testFs.MkdirAll("inaccessible", 0755))
	defer testFs.Chmod("inaccessible", 0777)

	file := filepath.Join("inaccessible", "a")
	fd, err := testFs.Create(file)
	must(t, err)
	fd.Close()

	m := setupModel(w)
	defer cleanupModel(m)

	must(t, testFs.Chmod("inaccessible", 0000))

	m.ScanFolder("default")

	if file, ok := m.CurrentFolderFile("default", file); !ok {
		t.Fatalf("File missing in db")
	} else if file.Deleted {
		t.Errorf("Inaccessible file has been marked as deleted.")
	}
}

// TestInternalScan checks whether various fs operations are correctly represented
// in the db after scanning.
func TestInternalScan(t *testing.T) {
	w, fcfg := tmpDefaultWrapper()
	testFs := fcfg.Filesystem()
	defer os.RemoveAll(testFs.URI())

	testCases := map[string]func(protocol.FileInfo) bool{
		"removeDir": func(f protocol.FileInfo) bool {
			return !f.Deleted
		},
		"dirToFile": func(f protocol.FileInfo) bool {
			return f.Deleted || f.IsDirectory()
		},
	}

	baseDirs := []string{"dirToFile", "removeDir"}
	for _, dir := range baseDirs {
		sub := filepath.Join(dir, "subDir")
		for _, dir := range []string{dir, sub} {
			if err := testFs.MkdirAll(dir, 0775); err != nil {
				t.Fatalf("%v: %v", dir, err)
			}
		}
		testCases[sub] = func(f protocol.FileInfo) bool {
			return !f.Deleted
		}
		for _, dir := range []string{dir, sub} {
			file := filepath.Join(dir, "a")
			fd, err := testFs.Create(file)
			must(t, err)
			fd.Close()
			testCases[file] = func(f protocol.FileInfo) bool {
				return !f.Deleted
			}
		}
	}

	m := setupModel(w)
	defer cleanupModel(m)

	for _, dir := range baseDirs {
		must(t, testFs.RemoveAll(dir))
	}

	fd, err := testFs.Create("dirToFile")
	must(t, err)
	fd.Close()

	m.ScanFolder("default")

	for path, cond := range testCases {
		if f, ok := m.CurrentFolderFile("default", path); !ok {
			t.Fatalf("%v missing in db", path)
		} else if cond(f) {
			t.Errorf("Incorrect db entry for %v", path)
		}
	}
}

func TestCustomMarkerName(t *testing.T) {
	testOs := &fatalOs{t}

	ldb := db.NewLowlevel(backend.OpenMemory())
	set := db.NewFileSet("default", defaultFs, ldb)
	set.Update(protocol.LocalDeviceID, []protocol.FileInfo{
		{Name: "dummyfile"},
	})

	fcfg := testFolderConfigTmp()
	fcfg.ID = "default"
	fcfg.RescanIntervalS = 1
	fcfg.MarkerName = "myfile"
	cfg := createTmpWrapper(config.Configuration{
		Folders: []config.FolderConfiguration{fcfg},
		Devices: []config.DeviceConfiguration{
			{
				DeviceID: device1,
			},
		},
	})

	testOs.RemoveAll(fcfg.Path)

	m := newModel(cfg, myID, "syncthing", "dev", ldb, nil)
	sub := m.evLogger.Subscribe(events.StateChanged)
	defer sub.Unsubscribe()
	m.ServeBackground()
	defer cleanupModelAndRemoveDir(m, fcfg.Path)

	waitForState(t, sub, "default", "folder path missing")

	testOs.Mkdir(fcfg.Path, 0700)
	fd := testOs.Create(filepath.Join(fcfg.Path, "myfile"))
	fd.Close()

	waitForState(t, sub, "default", "")
}

func TestRemoveDirWithContent(t *testing.T) {
	defer func() {
		defaultFs.RemoveAll("dirwith")
	}()

	defaultFs.MkdirAll("dirwith", 0755)
	content := filepath.Join("dirwith", "content")
	fd, err := defaultFs.Create(content)
	must(t, err)
	fd.Close()

	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	dir, ok := m.CurrentFolderFile("default", "dirwith")
	if !ok {
		t.Fatalf("Can't get dir \"dirwith\" after initial scan")
	}
	dir.Deleted = true
	dir.Version = dir.Version.Update(device1.Short()).Update(device1.Short())

	file, ok := m.CurrentFolderFile("default", content)
	if !ok {
		t.Fatalf("Can't get file \"%v\" after initial scan", content)
	}
	file.Deleted = true
	file.Version = file.Version.Update(device1.Short()).Update(device1.Short())

	m.IndexUpdate(device1, "default", []protocol.FileInfo{dir, file})

	// Is there something we could trigger on instead of just waiting?
	timeout := time.NewTimer(5 * time.Second)
	for {
		dir, ok := m.CurrentFolderFile("default", "dirwith")
		if !ok {
			t.Fatalf("Can't get dir \"dirwith\" after index update")
		}
		file, ok := m.CurrentFolderFile("default", content)
		if !ok {
			t.Fatalf("Can't get file \"%v\" after index update", content)
		}
		if dir.Deleted && file.Deleted {
			return
		}

		select {
		case <-timeout.C:
			if !dir.Deleted && !file.Deleted {
				t.Errorf("Neither the dir nor its content was deleted before timing out.")
			} else if !dir.Deleted {
				t.Errorf("The dir was not deleted before timing out.")
			} else {
				t.Errorf("The content of the dir was not deleted before timing out.")
			}
			return
		default:
			time.Sleep(100 * time.Millisecond)
		}
	}
}

func TestIssue4475(t *testing.T) {
	m, conn, fcfg := setupModelWithConnection()
	defer cleanupModel(m)
	testFs := fcfg.Filesystem()

	// Scenario: Dir is deleted locally and before syncing/index exchange
	// happens, a file is create in that dir on the remote.
	// This should result in the directory being recreated and added to the
	// db locally.

	must(t, testFs.MkdirAll("delDir", 0755))

	m.ScanFolder("default")

	if fcfg, ok := m.cfg.Folder("default"); !ok || !fcfg.SharedWith(device1) {
		t.Fatal("not shared with device1")
	}

	fileName := filepath.Join("delDir", "file")
	conn.addFile(fileName, 0644, protocol.FileInfoTypeFile, nil)
	conn.sendIndexUpdate()

	// Is there something we could trigger on instead of just waiting?
	timeout := time.NewTimer(5 * time.Second)
	created := false
	for {
		if !created {
			if _, ok := m.CurrentFolderFile("default", fileName); ok {
				created = true
			}
		} else {
			dir, ok := m.CurrentFolderFile("default", "delDir")
			if !ok {
				t.Fatalf("can't get dir from db")
			}
			if !dir.Deleted {
				return
			}
		}

		select {
		case <-timeout.C:
			if created {
				t.Errorf("Timed out before file from remote was created")
			} else {
				t.Errorf("Timed out before directory was resurrected in db")
			}
			return
		default:
			time.Sleep(100 * time.Millisecond)
		}
	}
}

func TestVersionRestore(t *testing.T) {
	// We create a bunch of files which we restore
	// In each file, we write the filename as the content
	// We verify that the content matches at the expected filenames
	// after the restore operation.
	dir, err := ioutil.TempDir("", "")
	must(t, err)
	defer os.RemoveAll(dir)

	fcfg := config.NewFolderConfiguration(myID, "default", "default", fs.FilesystemTypeBasic, dir)
	fcfg.Versioning.Type = "simple"
	fcfg.FSWatcherEnabled = false
	filesystem := fcfg.Filesystem()

	rawConfig := config.Configuration{
		Folders: []config.FolderConfiguration{fcfg},
	}
	cfg := createTmpWrapper(rawConfig)

	m := setupModel(cfg)
	defer cleanupModel(m)
	m.ScanFolder("default")

	sentinel, err := time.ParseInLocation(versioner.TimeFormat, "20180101-010101", time.Local)
	if err != nil {
		t.Fatal(err)
	}

	for _, file := range []string{
		// Versions directory
		".stversions/file~20171210-040404.txt",  // will be restored
		".stversions/existing~20171210-040404",  // exists, should expect to be archived.
		".stversions/something~20171210-040404", // will become directory, hence error
		".stversions/dir/file~20171210-040404.txt",
		".stversions/dir/file~20171210-040405.txt",
		".stversions/dir/file~20171210-040406.txt",
		".stversions/very/very/deep/one~20171210-040406.txt", // lives deep down, no directory exists.
		".stversions/dir/existing~20171210-040406.txt",       // exists, should expect to be archived.
		".stversions/dir/cat",                                // untagged which was used by trashcan, supported

		// "file.txt" will be restored
		"existing",
		"something/file", // Becomes directory
		"dir/file.txt",
		"dir/existing.txt",
	} {
		if runtime.GOOS == "windows" {
			file = filepath.FromSlash(file)
		}
		dir := filepath.Dir(file)
		must(t, filesystem.MkdirAll(dir, 0755))
		if fd, err := filesystem.Create(file); err != nil {
			t.Fatal(err)
		} else if _, err := fd.Write([]byte(file)); err != nil {
			t.Fatal(err)
		} else if err := fd.Close(); err != nil {
			t.Fatal(err)
		} else if err := filesystem.Chtimes(file, sentinel, sentinel); err != nil {
			t.Fatal(err)
		}
	}

	versions, err := m.GetFolderVersions("default")
	must(t, err)
	expectedVersions := map[string]int{
		"file.txt":               1,
		"existing":               1,
		"something":              1,
		"dir/file.txt":           3,
		"dir/existing.txt":       1,
		"very/very/deep/one.txt": 1,
		"dir/cat":                1,
	}

	for name, vers := range versions {
		cnt, ok := expectedVersions[name]
		if !ok {
			t.Errorf("unexpected %s", name)
		}
		if len(vers) != cnt {
			t.Errorf("%s: %d != %d", name, cnt, len(vers))
		}
		// Delete, so we can check if we didn't hit something we expect afterwards.
		delete(expectedVersions, name)
	}

	for name := range expectedVersions {
		t.Errorf("not found expected %s", name)
	}

	// Restoring non existing folder fails.
	_, err = m.RestoreFolderVersions("does not exist", nil)
	if err == nil {
		t.Errorf("expected an error")
	}

	makeTime := func(s string) time.Time {
		tm, err := time.ParseInLocation(versioner.TimeFormat, s, time.Local)
		if err != nil {
			t.Error(err)
		}
		return tm.Truncate(time.Second)
	}

	restore := map[string]time.Time{
		"file.txt":               makeTime("20171210-040404"),
		"existing":               makeTime("20171210-040404"),
		"something":              makeTime("20171210-040404"),
		"dir/file.txt":           makeTime("20171210-040406"),
		"dir/existing.txt":       makeTime("20171210-040406"),
		"very/very/deep/one.txt": makeTime("20171210-040406"),
	}

	beforeRestore := time.Now().Truncate(time.Second)

	ferr, err := m.RestoreFolderVersions("default", restore)
	must(t, err)

	if err, ok := ferr["something"]; len(ferr) > 1 || !ok || err != "cannot restore on top of a directory" {
		t.Fatalf("incorrect error or count: %d %s", len(ferr), ferr)
	}

	// Failed items are not expected to be restored.
	// Remove them from expectations
	for name := range ferr {
		delete(restore, name)
	}

	// Check that content of files matches to the version they've been restored.
	for file, version := range restore {
		if runtime.GOOS == "windows" {
			file = filepath.FromSlash(file)
		}
		tag := version.In(time.Local).Truncate(time.Second).Format(versioner.TimeFormat)
		taggedName := filepath.Join(".stversions", versioner.TagFilename(file, tag))
		fd, err := filesystem.Open(file)
		if err != nil {
			t.Error(err)
		}
		defer fd.Close()

		content, err := ioutil.ReadAll(fd)
		if err != nil {
			t.Error(err)
		}
		if !bytes.Equal(content, []byte(taggedName)) {
			t.Errorf("%s: %s != %s", file, string(content), taggedName)
		}
	}

	// Simple versioner uses now for timestamp generation, so we can check
	// if existing stuff was correctly archived as we restored (oppose to deleteD), and version time as after beforeRestore
	expectArchived := map[string]struct{}{
		"existing":         {},
		"dir/file.txt":     {},
		"dir/existing.txt": {},
	}

	allFileVersions, err := m.GetFolderVersions("default")
	must(t, err)
	for file, versions := range allFileVersions {
		key := file
		if runtime.GOOS == "windows" {
			file = filepath.FromSlash(file)
		}
		for _, version := range versions {
			if version.VersionTime.Equal(beforeRestore) || version.VersionTime.After(beforeRestore) {
				fd, err := filesystem.Open(".stversions/" + versioner.TagFilename(file, version.VersionTime.Format(versioner.TimeFormat)))
				must(t, err)
				defer fd.Close()

				content, err := ioutil.ReadAll(fd)
				if err != nil {
					t.Error(err)
				}
				// Even if they are at the archived path, content should have the non
				// archived name.
				if !bytes.Equal(content, []byte(file)) {
					t.Errorf("%s (%s): %s != %s", file, fd.Name(), string(content), file)
				}
				_, ok := expectArchived[key]
				if !ok {
					t.Error("unexpected archived file with future timestamp", file, version.VersionTime)
				}
				delete(expectArchived, key)
			}
		}
	}

	if len(expectArchived) != 0 {
		t.Fatal("missed some archived files", expectArchived)
	}
}

func TestPausedFolders(t *testing.T) {
	// Create a separate wrapper not to pollute other tests.
	wrapper := createTmpWrapper(defaultCfgWrapper.RawCopy())
	m := setupModel(wrapper)
	defer cleanupModel(m)

	if err := m.ScanFolder("default"); err != nil {
		t.Error(err)
	}

	pausedConfig := wrapper.RawCopy()
	pausedConfig.Folders[0].Paused = true
	w, err := m.cfg.Replace(pausedConfig)
	must(t, err)
	w.Wait()

	if err := m.ScanFolder("default"); err != ErrFolderPaused {
		t.Errorf("Expected folder paused error, received: %v", err)
	}

	if err := m.ScanFolder("nonexistent"); err != errFolderMissing {
		t.Errorf("Expected missing folder error, received: %v", err)
	}
}

func TestIssue4094(t *testing.T) {
	testOs := &fatalOs{t}

	db := db.NewLowlevel(backend.OpenMemory())
	// Create a separate wrapper not to pollute other tests.
	wrapper := createTmpWrapper(config.Configuration{})
	m := newModel(wrapper, myID, "syncthing", "dev", db, nil)
	m.ServeBackground()
	defer cleanupModel(m)

	// Force the model to wire itself and add the folders
	folderPath := "nonexistent"
	defer testOs.RemoveAll(folderPath)
	cfg := defaultCfgWrapper.RawCopy()
	fcfg := config.FolderConfiguration{
		ID:     "folder1",
		Path:   folderPath,
		Paused: true,
		Devices: []config.FolderDeviceConfiguration{
			{DeviceID: device1},
		},
	}
	cfg.Folders = []config.FolderConfiguration{fcfg}
	p, err := wrapper.Replace(cfg)
	must(t, err)
	p.Wait()

	if err := m.SetIgnores(fcfg.ID, []string{"foo"}); err != nil {
		t.Fatalf("failed setting ignores: %v", err)
	}

	if _, err := fcfg.Filesystem().Lstat(".stignore"); err != nil {
		t.Fatalf("failed stating .stignore: %v", err)
	}
}

func TestIssue4903(t *testing.T) {
	testOs := &fatalOs{t}

	db := db.NewLowlevel(backend.OpenMemory())
	// Create a separate wrapper not to pollute other tests.
	wrapper := createTmpWrapper(config.Configuration{})
	m := newModel(wrapper, myID, "syncthing", "dev", db, nil)
	m.ServeBackground()
	defer cleanupModel(m)

	// Force the model to wire itself and add the folders
	folderPath := "nonexistent"
	defer testOs.RemoveAll(folderPath)
	cfg := defaultCfgWrapper.RawCopy()
	fcfg := config.FolderConfiguration{
		ID:     "folder1",
		Path:   folderPath,
		Paused: true,
		Devices: []config.FolderDeviceConfiguration{
			{DeviceID: device1},
		},
	}
	cfg.Folders = []config.FolderConfiguration{fcfg}
	p, err := wrapper.Replace(cfg)
	must(t, err)
	p.Wait()

	if err := fcfg.CheckPath(); err != config.ErrPathMissing {
		t.Fatalf("expected path missing error, got: %v", err)
	}

	if _, err := fcfg.Filesystem().Lstat("."); !fs.IsNotExist(err) {
		t.Fatalf("Expected missing path error, got: %v", err)
	}
}

func TestIssue5002(t *testing.T) {
	// recheckFile should not panic when given an index equal to the number of blocks

	m := setupModel(defaultCfgWrapper)
	defer cleanupModel(m)

	if err := m.ScanFolder("default"); err != nil {
		t.Error(err)
	}

	file, ok := m.CurrentFolderFile("default", "foo")
	if !ok {
		t.Fatal("test file should exist")
	}
	blockSize := int32(file.BlockSize())

	m.recheckFile(protocol.LocalDeviceID, "default", "foo", file.Size-int64(blockSize), []byte{1, 2, 3, 4}, 0)
	m.recheckFile(protocol.LocalDeviceID, "default", "foo", file.Size, []byte{1, 2, 3, 4}, 0) // panic
	m.recheckFile(protocol.LocalDeviceID, "default", "foo", file.Size+int64(blockSize), []byte{1, 2, 3, 4}, 0)
}

func TestParentOfUnignored(t *testing.T) {
	m := newState(defaultCfg)
	defer cleanupModel(m)
	defer defaultFolderConfig.Filesystem().Remove(".stignore")

	m.SetIgnores("default", []string{"!quux", "*"})

	if parent, ok := m.CurrentFolderFile("default", "baz"); !ok {
		t.Errorf(`Directory "baz" missing in db`)
	} else if parent.IsIgnored() {
		t.Errorf(`Directory "baz" is ignored`)
	}
}

// TestFolderRestartZombies reproduces issue 5233, where multiple concurrent folder
// restarts would leave more than one folder runner alive.
func TestFolderRestartZombies(t *testing.T) {
	wrapper := createTmpWrapper(defaultCfg.Copy())
	opts := wrapper.Options()
	opts.RawMaxFolderConcurrency = -1
	wrapper.SetOptions(opts)
	folderCfg, _ := wrapper.Folder("default")
	folderCfg.FilesystemType = fs.FilesystemTypeFake
	wrapper.SetFolder(folderCfg)

	m := setupModel(wrapper)
	defer cleanupModel(m)

	// Make sure the folder is up and running, because we want to count it.
	m.ScanFolder("default")

	// Check how many running folders we have running before the test.
	if r := atomic.LoadInt32(&m.foldersRunning); r != 1 {
		t.Error("Expected one running folder, not", r)
	}

	// Run a few parallel configuration changers for one second. Each waits
	// for the commit to complete, but there are many of them.
	var wg sync.WaitGroup
	for i := 0; i < 25; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			t0 := time.Now()
			for time.Since(t0) < time.Second {
				cfg := folderCfg.Copy()
				cfg.MaxConflicts = rand.Int() // safe change that should cause a folder restart
				w, err := wrapper.SetFolder(cfg)
				if err != nil {
					panic(err)
				}
				w.Wait()
			}
		}()
	}

	// Wait for the above to complete and check how many folders we have
	// running now. It should not have increased.
	wg.Wait()
	// Make sure the folder is up and running, because we want to count it.
	m.ScanFolder("default")
	if r := atomic.LoadInt32(&m.foldersRunning); r != 1 {
		t.Error("Expected one running folder, not", r)
	}
}

func TestRequestLimit(t *testing.T) {
	wrapper := createTmpWrapper(defaultCfg.Copy())
	dev, _ := wrapper.Device(device1)
	dev.MaxRequestKiB = 1
	wrapper.SetDevice(dev)
	m, _ := setupModelWithConnectionFromWrapper(wrapper)
	defer cleanupModel(m)

	file := "tmpfile"
	befReq := time.Now()
	first, err := m.Request(device1, "default", file, 2000, 0, nil, 0, false)
	if err != nil {
		t.Fatalf("First request failed: %v", err)
	}
	reqDur := time.Since(befReq)
	returned := make(chan struct{})
	go func() {
		second, err := m.Request(device1, "default", file, 2000, 0, nil, 0, false)
		if err != nil {
			t.Errorf("Second request failed: %v", err)
		}
		close(returned)
		second.Close()
	}()
	time.Sleep(10 * reqDur)
	select {
	case <-returned:
		t.Fatalf("Second request returned before first was done")
	default:
	}
	first.Close()
	select {
	case <-returned:
	case <-time.After(time.Second):
		t.Fatalf("Second request did not return after first was done")
	}
}

func TestSanitizePath(t *testing.T) {
	cases := [][2]string{
		{"", ""},
		{"foo", "foo"},
		{`\*/foo\?/bar[{!@$%^&*#()}]`, "foo bar ()"},
		{"Räksmörgås", "Räksmörgås"},
		{`Räk \/ smörgås`, "Räk smörgås"},
		{"هذا هو *\x07?اسم الملف", "هذا هو اسم الملف"},
		{`../foo.txt`, `.. foo.txt`},
		{"  \t \n filename in  \t space\r", "filename in space"},
		{"你\xff好", `你 好`},
		{"\000 foo", "foo"},
	}

	for _, tc := range cases {
		res := sanitizePath(tc[0])
		if res != tc[1] {
			t.Errorf("sanitizePath(%q) => %q, expected %q", tc[0], res, tc[1])
		}
	}
}

// Fuzz test: sanitizePath must always return strings of printable UTF-8
// characters when fed random data.
//
// Note that space is considered printable, but other whitespace runes are not.
func TestSanitizePathFuzz(t *testing.T) {
	buf := make([]byte, 128)

	for i := 0; i < 100; i++ {
		rand.Read(buf)
		path := sanitizePath(string(buf))
		if !utf8.ValidString(path) {
			t.Errorf("sanitizePath(%q) => %q, not valid UTF-8", buf, path)
			continue
		}
		for _, c := range path {
			if !unicode.IsPrint(c) {
				t.Errorf("non-printable rune %q in sanitized path", c)
			}
		}
	}
}

// TestConnCloseOnRestart checks that there is no deadlock when calling Close
// on a protocol connection that has a blocking reader (blocking writer can't
// be done as the test requires clusterconfigs to go through).
func TestConnCloseOnRestart(t *testing.T) {
	oldCloseTimeout := protocol.CloseTimeout
	protocol.CloseTimeout = 100 * time.Millisecond
	defer func() {
		protocol.CloseTimeout = oldCloseTimeout
	}()

	w, fcfg := tmpDefaultWrapper()
	m := setupModel(w)
	defer cleanupModelAndRemoveDir(m, fcfg.Filesystem().URI())

	br := &testutils.BlockingRW{}
	nw := &testutils.NoopRW{}
	m.AddConnection(newFakeProtoConn(protocol.NewConnection(device1, br, nw, m, "testConn", protocol.CompressNever)), protocol.HelloResult{})
	m.pmut.RLock()
	if len(m.closed) != 1 {
		t.Fatalf("Expected just one conn (len(m.conn) == %v)", len(m.conn))
	}
	closed := m.closed[device1]
	m.pmut.RUnlock()

	newFcfg := fcfg.Copy()
	newFcfg.Paused = true
	done := make(chan struct{})
	go func() {
		m.restartFolder(fcfg, newFcfg, false)
		close(done)
	}()
	select {
	case <-done:
	case <-time.After(5 * time.Second):
		t.Fatal("Timed out before folder restart returned")
	}
	select {
	case <-closed:
	case <-time.After(5 * time.Second):
		t.Fatal("Timed out before connection was closed")
	}
}

func TestModTimeWindow(t *testing.T) {
	w, fcfg := tmpDefaultWrapper()
	tfs := fcfg.Filesystem()
	fcfg.RawModTimeWindowS = 2
	w.SetFolder(fcfg)
	m := setupModel(w)
	defer cleanupModelAndRemoveDir(m, tfs.URI())

	name := "foo"

	fd, err := tfs.Create(name)
	must(t, err)
	stat, err := fd.Stat()
	must(t, err)
	modTime := stat.ModTime()
	fd.Close()

	m.ScanFolders()

	// Get current version

	fi, ok := m.CurrentFolderFile("default", name)
	if !ok {
		t.Fatal("File missing")
	}
	v := fi.Version

	// Update time on disk 1s

	err = tfs.Chtimes(name, time.Now(), modTime.Add(time.Second))
	must(t, err)

	m.ScanFolders()

	// No change due to within window

	fi, _ = m.CurrentFolderFile("default", name)
	if !fi.Version.Equal(v) {
		t.Fatalf("Got version %v, expected %v", fi.Version, v)
	}

	// Update to be outside window

	err = tfs.Chtimes(name, time.Now(), modTime.Add(2*time.Second))
	must(t, err)

	m.ScanFolders()

	// Version should have updated

	fi, _ = m.CurrentFolderFile("default", name)
	if fi.Version.Compare(v) != protocol.Greater {
		t.Fatalf("Got result %v, expected %v", fi.Version.Compare(v), protocol.Greater)
	}
}

func TestDevicePause(t *testing.T) {
	m, _, fcfg := setupModelWithConnection()
	defer cleanupModelAndRemoveDir(m, fcfg.Filesystem().URI())

	sub := m.evLogger.Subscribe(events.DevicePaused)
	defer sub.Unsubscribe()

	m.pmut.RLock()
	closed := m.closed[device1]
	m.pmut.RUnlock()

	dev := m.cfg.Devices()[device1]
	dev.Paused = true
	m.cfg.SetDevice(dev)

	timeout := time.NewTimer(5 * time.Second)
	select {
	case <-sub.C():
		select {
		case <-closed:
		case <-timeout.C:
			t.Fatal("Timed out before connection was closed")
		}
	case <-timeout.C:
		t.Fatal("Timed out before device was paused")
	}
}

func TestDeviceWasSeen(t *testing.T) {
	m, _, fcfg := setupModelWithConnection()
	defer cleanupModelAndRemoveDir(m, fcfg.Filesystem().URI())

	m.deviceWasSeen(device1)

	stats, err := m.DeviceStatistics()
	if err != nil {
		t.Error("Unexpected error:", err)
	}
	entry := stats[device1.String()]
	if time.Since(entry.LastSeen) > time.Second {
		t.Error("device should have been seen now")
	}
}

func TestNewLimitedRequestResponse(t *testing.T) {
	l0 := newByteSemaphore(0)
	l1 := newByteSemaphore(1024)
	l2 := (*byteSemaphore)(nil)

	// Should take 500 bytes from any non-unlimited non-nil limiters.
	res := newLimitedRequestResponse(500, l0, l1, l2)

	if l1.available != 1024-500 {
		t.Error("should have taken bytes from limited limiter")
	}

	// Closing the result should return the bytes.
	res.Close()

	// Try to take 1024 bytes to make sure the bytes were returned.
	done := make(chan struct{})
	go func() {
		l1.take(1024)
		close(done)
	}()
	select {
	case <-done:
	case <-time.After(time.Second):
		t.Error("Bytes weren't returned in a timely fashion")
	}
}

func TestSummaryPausedNoError(t *testing.T) {
	wcfg, fcfg := tmpDefaultWrapper()
	fcfg.Paused = true
	wcfg.SetFolder(fcfg)
	m := setupModel(wcfg)
	defer cleanupModel(m)

	fss := NewFolderSummaryService(wcfg, m, myID, events.NoopLogger)
	if _, err := fss.Summary(fcfg.ID); err != nil {
		t.Error("Expected no error getting a summary for a paused folder:", err)
	}
}

func TestFolderAPIErrors(t *testing.T) {
	wcfg, fcfg := tmpDefaultWrapper()
	fcfg.Paused = true
	wcfg.SetFolder(fcfg)
	m := setupModel(wcfg)
	defer cleanupModel(m)

	methods := []func(folder string) error{
		m.ScanFolder,
		func(folder string) error {
			return m.ScanFolderSubdirs(folder, nil)
		},
		func(folder string) error {
			_, err := m.GetFolderVersions(folder)
			return err
		},
		func(folder string) error {
			_, err := m.RestoreFolderVersions(folder, nil)
			return err
		},
	}

	for i, method := range methods {
		if err := method(fcfg.ID); err != ErrFolderPaused {
			t.Errorf(`Expected "%v", got "%v" (method no %v)`, ErrFolderPaused, err, i)
		}
		if err := method("notexisting"); err != errFolderMissing {
			t.Errorf(`Expected "%v", got "%v" (method no %v)`, errFolderMissing, err, i)
		}
	}
}

func TestRenameSequenceOrder(t *testing.T) {
	wcfg, fcfg := tmpDefaultWrapper()
	m := setupModel(wcfg)
	defer cleanupModel(m)

	numFiles := 20

	ffs := fcfg.Filesystem()
	for i := 0; i < numFiles; i++ {
		v := fmt.Sprintf("%d", i)
		must(t, writeFile(ffs, v, []byte(v), 0644))
	}

	m.ScanFolders()

	count := 0
	snap := dbSnapshot(t, m, "default")
	snap.WithHave(protocol.LocalDeviceID, func(i protocol.FileIntf) bool {
		count++
		return true
	})
	snap.Release()

	if count != numFiles {
		t.Errorf("Unexpected count: %d != %d", count, numFiles)
	}

	// Modify all the files, other than the ones we expect to rename
	for i := 0; i < numFiles; i++ {
		if i == 3 || i == 17 || i == 16 || i == 4 {
			continue
		}
		v := fmt.Sprintf("%d", i)
		must(t, writeFile(ffs, v, []byte(v+"-new"), 0644))
	}
	// Rename
	must(t, ffs.Rename("3", "17"))
	must(t, ffs.Rename("16", "4"))

	// Scan
	m.ScanFolders()

	// Verify sequence of a appearing is followed by c disappearing.
	snap = dbSnapshot(t, m, "default")
	defer snap.Release()

	var firstExpectedSequence int64
	var secondExpectedSequence int64
	failed := false
	snap.WithHaveSequence(0, func(i protocol.FileIntf) bool {
		t.Log(i)
		if i.FileName() == "17" {
			firstExpectedSequence = i.SequenceNo() + 1
		}
		if i.FileName() == "4" {
			secondExpectedSequence = i.SequenceNo() + 1
		}
		if i.FileName() == "3" {
			failed = i.SequenceNo() != firstExpectedSequence || failed
		}
		if i.FileName() == "16" {
			failed = i.SequenceNo() != secondExpectedSequence || failed
		}
		return true
	})
	if failed {
		t.Fail()
	}
}

func TestRenameSameFile(t *testing.T) {
	wcfg, fcfg := tmpDefaultWrapper()
	m := setupModel(wcfg)
	defer cleanupModel(m)

	ffs := fcfg.Filesystem()
	must(t, writeFile(ffs, "file", []byte("file"), 0644))

	m.ScanFolders()

	count := 0
	snap := dbSnapshot(t, m, "default")
	snap.WithHave(protocol.LocalDeviceID, func(i protocol.FileIntf) bool {
		count++
		return true
	})
	snap.Release()

	if count != 1 {
		t.Errorf("Unexpected count: %d != %d", count, 1)
	}

	must(t, ffs.Rename("file", "file1"))
	must(t, osutil.Copy(fs.CopyRangeMethodStandard, ffs, ffs, "file1", "file0"))
	must(t, osutil.Copy(fs.CopyRangeMethodStandard, ffs, ffs, "file1", "file2"))
	must(t, osutil.Copy(fs.CopyRangeMethodStandard, ffs, ffs, "file1", "file3"))
	must(t, osutil.Copy(fs.CopyRangeMethodStandard, ffs, ffs, "file1", "file4"))

	m.ScanFolders()

	snap = dbSnapshot(t, m, "default")
	defer snap.Release()

	prevSeq := int64(0)
	seen := false
	snap.WithHaveSequence(0, func(i protocol.FileIntf) bool {
		if i.SequenceNo() <= prevSeq {
			t.Fatalf("non-increasing sequences: %d <= %d", i.SequenceNo(), prevSeq)
		}
		if i.FileName() == "file" {
			if seen {
				t.Fatal("already seen file")
			}
			seen = true
		}
		prevSeq = i.SequenceNo()
		return true
	})
}

func TestRenameEmptyFile(t *testing.T) {
	wcfg, fcfg := tmpDefaultWrapper()
	m := setupModel(wcfg)
	defer cleanupModel(m)

	ffs := fcfg.Filesystem()

	must(t, writeFile(ffs, "file", []byte("data"), 0644))
	must(t, writeFile(ffs, "empty", nil, 0644))

	m.ScanFolders()

	snap := dbSnapshot(t, m, "default")
	defer snap.Release()
	empty, eok := snap.Get(protocol.LocalDeviceID, "empty")
	if !eok {
		t.Fatal("failed to find empty file")
	}
	file, fok := snap.Get(protocol.LocalDeviceID, "file")
	if !fok {
		t.Fatal("failed to find non-empty file")
	}

	count := 0
	snap.WithBlocksHash(empty.BlocksHash, func(_ protocol.FileIntf) bool {
		count++
		return true
	})

	if count != 0 {
		t.Fatalf("Found %d entries for empty file, expected 0", count)
	}

	count = 0
	snap.WithBlocksHash(file.BlocksHash, func(_ protocol.FileIntf) bool {
		count++
		return true
	})

	if count != 1 {
		t.Fatalf("Found %d entries for non-empty file, expected 1", count)
	}

	must(t, ffs.Rename("file", "new-file"))
	must(t, ffs.Rename("empty", "new-empty"))

	// Scan
	m.ScanFolders()

	snap = dbSnapshot(t, m, "default")
	defer snap.Release()

	count = 0
	snap.WithBlocksHash(empty.BlocksHash, func(_ protocol.FileIntf) bool {
		count++
		return true
	})

	if count != 0 {
		t.Fatalf("Found %d entries for empty file, expected 0", count)
	}

	count = 0
	snap.WithBlocksHash(file.BlocksHash, func(i protocol.FileIntf) bool {
		count++
		if i.FileName() != "new-file" {
			t.Fatalf("unexpected file name %s, expected new-file", i.FileName())
		}
		return true
	})

	if count != 1 {
		t.Fatalf("Found %d entries for non-empty file, expected 1", count)
	}
}

func TestBlockListMap(t *testing.T) {
	wcfg, fcfg := tmpDefaultWrapper()
	m := setupModel(wcfg)
	defer cleanupModel(m)

	ffs := fcfg.Filesystem()
	must(t, writeFile(ffs, "one", []byte("content"), 0644))
	must(t, writeFile(ffs, "two", []byte("content"), 0644))
	must(t, writeFile(ffs, "three", []byte("content"), 0644))
	must(t, writeFile(ffs, "four", []byte("content"), 0644))
	must(t, writeFile(ffs, "five", []byte("content"), 0644))

	m.ScanFolders()

	snap := dbSnapshot(t, m, "default")
	defer snap.Release()
	fi, ok := snap.Get(protocol.LocalDeviceID, "one")
	if !ok {
		t.Error("failed to find existing file")
	}
	var paths []string

	snap.WithBlocksHash(fi.BlocksHash, func(fi protocol.FileIntf) bool {
		paths = append(paths, fi.FileName())
		return true
	})
	snap.Release()

	expected := []string{"one", "two", "three", "four", "five"}
	if !equalStringsInAnyOrder(paths, expected) {
		t.Errorf("expected %q got %q", expected, paths)
	}

	// Fudge the files around
	// Remove
	must(t, ffs.Remove("one"))

	// Modify
	must(t, ffs.Remove("two"))
	must(t, writeFile(ffs, "two", []byte("mew-content"), 0644))

	// Rename
	must(t, ffs.Rename("three", "new-three"))

	// Change type
	must(t, ffs.Remove("four"))
	must(t, ffs.Mkdir("four", 0644))

	m.ScanFolders()

	// Check we're left with 2 of the 5
	snap = dbSnapshot(t, m, "default")
	defer snap.Release()

	paths = paths[:0]
	snap.WithBlocksHash(fi.BlocksHash, func(fi protocol.FileIntf) bool {
		paths = append(paths, fi.FileName())
		return true
	})
	snap.Release()

	expected = []string{"new-three", "five"}
	if !equalStringsInAnyOrder(paths, expected) {
		t.Errorf("expected %q got %q", expected, paths)
	}
}

func TestScanRenameCaseOnly(t *testing.T) {
	wcfg, fcfg := tmpDefaultWrapper()
	m := setupModel(wcfg)
	defer cleanupModel(m)

	ffs := fcfg.Filesystem()
	name := "foo"
	must(t, writeFile(ffs, name, []byte("contents"), 0644))

	m.ScanFolders()

	snap := dbSnapshot(t, m, fcfg.ID)
	defer snap.Release()
	found := false
	snap.WithHave(protocol.LocalDeviceID, func(i protocol.FileIntf) bool {
		if found {
			t.Fatal("got more than one file")
		}
		if i.FileName() != name {
			t.Fatalf("got file %v, expected %v", i.FileName(), name)
		}
		found = true
		return true
	})
	snap.Release()

	upper := strings.ToUpper(name)
	must(t, ffs.Rename(name, upper))
	m.ScanFolders()

	snap = dbSnapshot(t, m, fcfg.ID)
	defer snap.Release()
	found = false
	snap.WithHave(protocol.LocalDeviceID, func(i protocol.FileIntf) bool {
		if i.FileName() == name {
			if i.IsDeleted() {
				return true
			}
			t.Fatal("renamed file not deleted")
		}
		if i.FileName() != upper {
			t.Fatalf("got file %v, expected %v", i.FileName(), upper)
		}
		if found {
			t.Fatal("got more than the expected files")
		}
		found = true
		return true
	})
}

func TestConnectionTerminationOnFolderAdd(t *testing.T) {
	testConfigChangeClosesConnections(t, false, true, nil, func(cfg config.Wrapper) {
		fcfg := testFolderConfigTmp()
		fcfg.ID = "second"
		fcfg.Label = "second"
		fcfg.Devices = []config.FolderDeviceConfiguration{{device2, protocol.EmptyDeviceID}}
		if w, err := cfg.SetFolder(fcfg); err != nil {
			t.Fatal(err)
		} else {
			w.Wait()
		}
	})
}

func TestConnectionTerminationOnFolderShare(t *testing.T) {
	testConfigChangeClosesConnections(t, true, true, nil, func(cfg config.Wrapper) {
		fcfg := cfg.FolderList()[0]
		fcfg.Devices = []config.FolderDeviceConfiguration{{device2, protocol.EmptyDeviceID}}
		if w, err := cfg.SetFolder(fcfg); err != nil {
			t.Fatal(err)
		} else {
			w.Wait()
		}
	})
}

func TestConnectionTerminationOnFolderUnshare(t *testing.T) {
	testConfigChangeClosesConnections(t, true, false, nil, func(cfg config.Wrapper) {
		fcfg := cfg.FolderList()[0]
		fcfg.Devices = nil
		if w, err := cfg.SetFolder(fcfg); err != nil {
			t.Fatal(err)
		} else {
			w.Wait()
		}
	})
}

func TestConnectionTerminationOnFolderRemove(t *testing.T) {
	testConfigChangeClosesConnections(t, true, false, nil, func(cfg config.Wrapper) {
		rcfg := cfg.RawCopy()
		rcfg.Folders = nil
		if w, err := cfg.Replace(rcfg); err != nil {
			t.Fatal(err)
		} else {
			w.Wait()
		}
	})
}

func TestConnectionTerminationOnFolderPause(t *testing.T) {
	testConfigChangeClosesConnections(t, true, false, nil, func(cfg config.Wrapper) {
		fcfg := cfg.FolderList()[0]
		fcfg.Paused = true
		if w, err := cfg.SetFolder(fcfg); err != nil {
			t.Fatal(err)
		} else {
			w.Wait()
		}
	})
}

func TestConnectionTerminationOnFolderUnpause(t *testing.T) {
	testConfigChangeClosesConnections(t, true, false, func(cfg config.Wrapper) {
		fcfg := cfg.FolderList()[0]
		fcfg.Paused = true
		if w, err := cfg.SetFolder(fcfg); err != nil {
			t.Fatal(err)
		} else {
			w.Wait()
		}
	}, func(cfg config.Wrapper) {
		fcfg := cfg.FolderList()[0]
		fcfg.Paused = false
		if w, err := cfg.SetFolder(fcfg); err != nil {
			t.Fatal(err)
		} else {
			w.Wait()
		}
	})
}

func TestAddFolderCompletion(t *testing.T) {
	// Empty folders are always 100% complete.
	comp := newFolderCompletion(db.Counts{}, db.Counts{}, 0)
	comp.add(newFolderCompletion(db.Counts{}, db.Counts{}, 0))
	if comp.CompletionPct != 100 {
		t.Error(comp.CompletionPct)
	}

	// Completion is of the whole
	comp = newFolderCompletion(db.Counts{Bytes: 100}, db.Counts{}, 0)             // 100% complete
	comp.add(newFolderCompletion(db.Counts{Bytes: 400}, db.Counts{Bytes: 50}, 0)) // 82.5% complete
	if comp.CompletionPct != 90 {                                                 // 100 * (1 - 50/500)
		t.Error(comp.CompletionPct)
	}
}

func TestScanDeletedROChangedOnSR(t *testing.T) {
	w, fcfg := tmpDefaultWrapper()
	fcfg.Type = config.FolderTypeReceiveOnly
	waiter, _ := w.SetFolder(fcfg)
	waiter.Wait()
	m := setupModel(w)
	defer cleanupModel(m)
	name := "foo"
	ffs := fcfg.Filesystem()

	must(t, writeFile(ffs, name, []byte(name), 0644))
	m.ScanFolders()

	file, ok := m.CurrentFolderFile(fcfg.ID, name)
	if !ok {
		t.Fatal("file missing in db")
	}
	// A remote must have the file, otherwise the deletion below is
	// automatically resolved as not a ro-changed item.
	m.IndexUpdate(device1, fcfg.ID, []protocol.FileInfo{file})

	must(t, ffs.Remove(name))
	m.ScanFolders()

	if receiveOnlyChangedSize(t, m, fcfg.ID).Deleted != 1 {
		t.Fatal("expected one receive only changed deleted item")
	}

	fcfg.Type = config.FolderTypeSendReceive
	waiter, _ = w.SetFolder(fcfg)
	waiter.Wait()
	m.ScanFolders()

	if receiveOnlyChangedSize(t, m, fcfg.ID).Deleted != 0 {
		t.Fatal("expected no receive only changed deleted item")
	}
	if localSize(t, m, fcfg.ID).Deleted != 1 {
		t.Fatal("expected one local deleted item")
	}
}

func testConfigChangeClosesConnections(t *testing.T, expectFirstClosed, expectSecondClosed bool, pre func(config.Wrapper), fn func(config.Wrapper)) {
	t.Helper()
	wcfg, _ := tmpDefaultWrapper()
	m := setupModel(wcfg)
	defer cleanupModel(m)

	_, err := wcfg.SetDevice(config.NewDeviceConfiguration(device2, "device2"))
	if err != nil {
		t.Fatal(err)
	}

	if pre != nil {
		pre(wcfg)
	}

	fc1 := &fakeConnection{id: device1, model: m}
	fc2 := &fakeConnection{id: device2, model: m}
	m.AddConnection(fc1, protocol.HelloResult{})
	m.AddConnection(fc2, protocol.HelloResult{})

	t.Log("Applying config change")

	fn(wcfg)

	if expectFirstClosed != fc1.closed {
		t.Errorf("first connection state mismatch: %t (expected) != %t", expectFirstClosed, fc1.closed)
	}

	if expectSecondClosed != fc2.closed {
		t.Errorf("second connection state mismatch: %t (expected) != %t", expectSecondClosed, fc2.closed)
	}
}

// The end result of the tested scenario is that the global version entry has an
// empty version vector and is not deleted, while everything is actually deleted.
// That then causes these files to be considered as needed, while they are not.
// https://github.com/syncthing/syncthing/issues/6961
func TestIssue6961(t *testing.T) {
	wcfg, fcfg := tmpDefaultWrapper()
	tfs := fcfg.Filesystem()
	wcfg.SetDevice(config.NewDeviceConfiguration(device2, "device2"))
	fcfg.Type = config.FolderTypeReceiveOnly
	fcfg.Devices = append(fcfg.Devices, config.FolderDeviceConfiguration{DeviceID: device2})
	wcfg.SetFolder(fcfg)
	// Always recalc/repair when opening a fileset.
	// db := db.NewLowlevel(backend.OpenMemory(), db.WithRecheckInterval(time.Millisecond))
	db := db.NewLowlevel(backend.OpenMemory())
	m := newModel(wcfg, myID, "syncthing", "dev", db, nil)
	m.ServeBackground()
	defer cleanupModelAndRemoveDir(m, tfs.URI())
	m.ScanFolders()

	name := "foo"
	version := protocol.Vector{}.Update(device1.Short())

	// Remote, valid and existing file
	m.Index(device1, fcfg.ID, []protocol.FileInfo{{Name: name, Version: version, Sequence: 1}})
	// Remote, invalid (receive-only) and existing file
	m.Index(device2, fcfg.ID, []protocol.FileInfo{{Name: name, RawInvalid: true, Sequence: 1}})
	// Create a local file
	if fd, err := tfs.OpenFile(name, fs.OptCreate, 0666); err != nil {
		t.Fatal(err)
	} else {
		fd.Close()
	}
	if info, err := tfs.Lstat(name); err != nil {
		t.Fatal(err)
	} else {
		l.Infoln("intest", info.Mode)
	}
	m.ScanFolders()

	// Get rid of valid global
	waiter, err := wcfg.RemoveDevice(device1)
	if err != nil {
		t.Fatal(err)
	}
	waiter.Wait()

	// Delete the local file
	must(t, tfs.Remove(name))
	m.ScanFolders()

	// Drop ther remote index, add some other file.
	m.Index(device2, fcfg.ID, []protocol.FileInfo{{Name: "bar", RawInvalid: true, Sequence: 1}})

	// Pause and unpause folder to create new db.FileSet and thus recalculate everything
	fcfg.Paused = true
	waiter, err = wcfg.SetFolder(fcfg)
	if err != nil {
		t.Fatal(err)
	}
	waiter.Wait()
	fcfg.Paused = false
	waiter, err = wcfg.SetFolder(fcfg)
	if err != nil {
		t.Fatal(err)
	}
	waiter.Wait()

	if comp := m.Completion(device2, fcfg.ID); comp.NeedDeletes != 0 {
		t.Error("Expected 0 needed deletes, got", comp.NeedDeletes)
	} else {
		t.Log(comp)
	}
}

func TestCompletionEmptyGlobal(t *testing.T) {
	wcfg, fcfg := tmpDefaultWrapper()
	m := setupModel(wcfg)
	defer cleanupModelAndRemoveDir(m, fcfg.Filesystem().URI())
	files := []protocol.FileInfo{{Name: "foo", Version: protocol.Vector{}.Update(myID.Short()), Sequence: 1}}
	m.fmut.Lock()
	m.folderFiles[fcfg.ID].Update(protocol.LocalDeviceID, files)
	m.fmut.Unlock()
	files[0].Deleted = true
	files[0].Version = files[0].Version.Update(device1.Short())
	m.IndexUpdate(device1, fcfg.ID, files)
	comp := m.Completion(protocol.LocalDeviceID, fcfg.ID)
	if comp.CompletionPct != 95 {
		t.Error("Expected completion of 95%, got", comp.CompletionPct)
	}
}

func equalStringsInAnyOrder(a, b []string) bool {
	if len(a) != len(b) {
		return false
	}
	sort.Strings(a)
	sort.Strings(b)
	for i := range a {
		if a[i] != b[i] {
			return false
		}
	}
	return true
}