Drop and warn about non-normalized file names on Linux/Windows (fixes #329)

integration/test.sh

@@ -21,6 +21,15 @@ start() {
 	done
 }
 
+clean() {
+	if [[ $(uname -s) == "Linux" ]] ; then
+		grep -v utf8-nfd
+	else
+		cat
+	fi
+}
+
+
 testConvergence() {
 	while true ; do
 		sleep 5
@@ -38,13 +47,13 @@ testConvergence() {
 	done
 
 	echo "Verifying..."
-	cat md5-? | sort | uniq > md5-tot
-	cat md5-12-? | sort | uniq > md5-12-tot
-	cat md5-23-? | sort | uniq > md5-23-tot
+	cat md5-? | sort | clean | uniq > md5-tot
+	cat md5-12-? | sort | clean | uniq > md5-12-tot
+	cat md5-23-? | sort | clean | uniq > md5-23-tot
 
 	for i in 1 2 3 12-1 12-2 23-2 23-3; do
 		pushd "s$i" >/dev/null
-		../md5r -l | sort > ../md5-$i
+		../md5r -l | sort | clean > ../md5-$i
 		popd >/dev/null
 	done
 

scanner/walk.go

@@ -13,6 +13,7 @@ import (
 	"runtime"
 	"strings"
 	"time"
+	"code.google.com/p/go.text/unicode/norm"
 
 	"github.com/calmh/syncthing/lamport"
 	"github.com/calmh/syncthing/protocol"
@@ -159,6 +160,11 @@ func (w *Walker) walkAndHashFiles(res *[]File, ign map[string][]string) filepath
 			return nil
 		}
 
+		if (runtime.GOOS == "linux" || runtime.GOOS == "windows") && !norm.NFC.IsNormalString(rn) {
+			l.Warnf("File %q contains non-NFC UTF-8 sequences and cannot be synced. Consider renaming.", rn)
+			return nil
+		}
+
 		if info.Mode().IsDir() {
 			if w.CurrentFiler != nil {
 				cf := w.CurrentFiler.CurrentFile(rn)