cmd/syncthing: Make directory auto-complete case insensitive (fixes #1347)

cmd/syncthing/gui.go

@@ -1542,6 +1542,24 @@ func (s *apiService) getSystemBrowse(w http.ResponseWriter, r *http.Request) {
 	sendJSON(w, browseFiles(current, fsType))
 }
 
+const (
+	matchExact int = iota
+	matchCaseIns
+	noMatch
+)
+
+func checkPrefixMatch(s, prefix string) int {
+	if strings.HasPrefix(s, prefix) {
+		return matchExact
+	}
+
+	if strings.HasPrefix(strings.ToLower(s), strings.ToLower(prefix)) {
+		return matchCaseIns
+	}
+
+	return noMatch
+}
+
 func browseFiles(current string, fsType fs.FilesystemType) []string {
 	if current == "" {
 		filesystem := fs.NewFilesystem(fsType, "")
@@ -1567,16 +1585,29 @@ func browseFiles(current string, fsType fs.FilesystemType) []string {
 
 	fs := fs.NewFilesystem(fsType, searchDir)
 
-	subdirectories, _ := fs.Glob(searchFile + "*")
+	subdirectories, _ := fs.DirNames(".")
+
+	exactMatches := make([]string, 0, len(subdirectories))
+	caseInsMatches := make([]string, 0, len(subdirectories))
 
-	ret := make([]string, 0, len(subdirectories))
 	for _, subdirectory := range subdirectories {
 		info, err := fs.Stat(subdirectory)
-		if err == nil && info.IsDir() {
-			ret = append(ret, filepath.Join(searchDir, subdirectory)+pathSeparator)
+		if err != nil || !info.IsDir() {
+			continue
+		}
+
+		switch checkPrefixMatch(subdirectory, searchFile) {
+		case matchExact:
+			exactMatches = append(exactMatches, filepath.Join(searchDir, subdirectory)+pathSeparator)
+		case matchCaseIns:
+			caseInsMatches = append(caseInsMatches, filepath.Join(searchDir, subdirectory)+pathSeparator)
 		}
 	}
-	return ret
+
+	// sort to return matches in deterministic order (don't depend on file system order)
+	sort.Strings(exactMatches)
+	sort.Strings(caseInsMatches)
+	return append(exactMatches, caseInsMatches...)
 }
 
 func (s *apiService) getCPUProf(w http.ResponseWriter, r *http.Request) {

cmd/syncthing/gui_test.go

@@ -988,10 +988,14 @@ func TestBrowse(t *testing.T) {
 	if err := ioutil.WriteFile(filepath.Join(tmpDir, "file"), []byte("hello"), 0644); err != nil {
 		t.Fatal(err)
 	}
+	if err := os.Mkdir(filepath.Join(tmpDir, "MiXEDCase"), 0755); err != nil {
+		t.Fatal(err)
+	}
 
 	// We expect completion to return the full path to the completed
 	// directory, with an ending slash.
 	dirPath := filepath.Join(tmpDir, "dir") + pathSep
+	mixedCaseDirPath := filepath.Join(tmpDir, "MiXEDCase") + pathSep
 
 	cases := []struct {
 		current string
@@ -1002,13 +1006,15 @@ func TestBrowse(t *testing.T) {
 		// With slash it's completed to its contents.
 		// Dirs are given pathSeps.
 		// Files are not returned.
-		{tmpDir + pathSep, []string{dirPath}},
+		{tmpDir + pathSep, []string{mixedCaseDirPath, dirPath}},
 		// Globbing is automatic based on prefix.
 		{tmpDir + pathSep + "d", []string{dirPath}},
 		{tmpDir + pathSep + "di", []string{dirPath}},
 		{tmpDir + pathSep + "dir", []string{dirPath}},
 		{tmpDir + pathSep + "f", nil},
 		{tmpDir + pathSep + "q", nil},
+		// Globbing is case-insensitve
+		{tmpDir + pathSep + "mixed", []string{mixedCaseDirPath}},
 	}
 
 	for _, tc := range cases {
@@ -1019,6 +1025,26 @@ func TestBrowse(t *testing.T) {
 	}
 }
 
+func TestPrefixMatch(t *testing.T) {
+	cases := []struct {
+		s        string
+		prefix   string
+		expected int
+	}{
+		{"aaaA", "aaa", matchExact},
+		{"AAAX", "BBB", noMatch},
+		{"AAAX", "aAa", matchCaseIns},
+		{"äÜX", "äü", matchCaseIns},
+	}
+
+	for _, tc := range cases {
+		ret := checkPrefixMatch(tc.s, tc.prefix)
+		if ret != tc.expected {
+			t.Errorf("checkPrefixMatch(%q, %q) => %v, expected %v", tc.s, tc.prefix, ret, tc.expected)
+		}
+	}
+}
+
 func equalStrings(a, b []string) bool {
 	if len(a) != len(b) {
 		return false