fix(ur): actually send usage report directly when enabled (#9736)

There was a bug that the unique ID was not set when reporting was
enabled, and thus the reports where rejected by the server. The unique
ID got set only on startup, so next time Syncthing restarted.

This makes sure to set the unique ID when blank.

lib/config/config_test.go

@@ -305,6 +305,11 @@ func TestOverriddenValues(t *testing.T) {
 		t.Error(err)
 	}
 
+	if cfg.Options().URUniqueID == "" {
+		t.Error("expected usage reporting unique ID to be set since usage reporting is enabled")
+	}
+	expected.URUniqueID = cfg.Options().URUniqueID // it's random
+
 	if diff, equal := messagediff.PrettyDiff(expected, cfg.Options()); !equal {
 		t.Errorf("Overridden config differs. Diff:\n%s", diff)
 	}

lib/config/optionsconfiguration.go

@@ -65,6 +65,11 @@ func (opts *OptionsConfiguration) prepare(guiPWIsSet bool) {
 		l.Warnln("Connection priority number for TCP over WAN must be worse (higher) than TCP over LAN. Correcting.")
 		opts.ConnectionPriorityTCPWAN = opts.ConnectionPriorityTCPLAN + 1
 	}
+
+	// If usage reporting is enabled we must have a unique ID.
+	if opts.URAccepted > 0 && opts.URUniqueID == "" {
+		opts.URUniqueID = rand.String(8)
+	}
 }
 
 // RequiresRestartOnly returns a copy with only the attributes that require

lib/syncthing/syncthing.go

@@ -36,7 +36,6 @@ import (
 	"github.com/syncthing/syncthing/lib/model"
 	"github.com/syncthing/syncthing/lib/osutil"
 	"github.com/syncthing/syncthing/lib/protocol"
-	"github.com/syncthing/syncthing/lib/rand"
 	"github.com/syncthing/syncthing/lib/svcutil"
 	"github.com/syncthing/syncthing/lib/tlsutil"
 	"github.com/syncthing/syncthing/lib/upgrade"
@@ -291,11 +290,6 @@ func (a *App) startup() error {
 				// Unique ID will be set and config saved below if necessary.
 			}
 		}
-
-		// If we are going to do usage reporting, ensure we have a valid unique ID.
-		if cfg.Options.URAccepted > 0 && cfg.Options.URUniqueID == "" {
-			cfg.Options.URUniqueID = rand.String(8)
-		}
 	})
 
 	usageReportingSvc := ur.New(a.cfg, m, connectionsService, a.opts.NoUpgrade)