lib/model: Consistent error return values for folder methods on model (#6325)

lib/model/folder_recvonly_test.go

@@ -48,7 +48,11 @@ func TestRecvOnlyRevertDeletes(t *testing.T) {
 	m.Index(device1, "ro", knownFiles)
 	f.updateLocalsFromScanning(knownFiles)
 
-	size := globalSize(t, m, "ro")
+	m.fmut.RLock()
+	snap := m.folderFiles["ro"].Snapshot()
+	m.fmut.RUnlock()
+	size := snap.GlobalSize()
+	snap.Release()
 	if size.Files != 1 || size.Directories != 1 {
 		t.Fatalf("Global: expected 1 file and 1 directory: %+v", size)
 	}

lib/model/model.go

@@ -840,10 +840,11 @@ func (m *model) Completion(device protocol.DeviceID, folder string) FolderComple
 // DBSnapshot returns a snapshot of the database content relevant to the given folder.
 func (m *model) DBSnapshot(folder string) (*db.Snapshot, error) {
 	m.fmut.RLock()
-	rf, ok := m.folderFiles[folder]
+	err := m.checkFolderRunningLocked(folder)
+	rf := m.folderFiles[folder]
 	m.fmut.RUnlock()
-	if !ok {
+	if err != nil {
-		return nil, errFolderMissing
+		return nil, err
 	}
 	return rf.Snapshot(), nil
 }
@@ -2319,10 +2320,11 @@ func (m *model) GlobalDirectoryTree(folder, prefix string, levels int, dirsonly
 
 func (m *model) GetFolderVersions(folder string) (map[string][]versioner.FileVersion, error) {
 	m.fmut.RLock()
-	ver, ok := m.folderVersioners[folder]
+	err := m.checkFolderRunningLocked(folder)
+	ver := m.folderVersioners[folder]
 	m.fmut.RUnlock()
-	if !ok {
+	if err != nil {
-		return nil, errFolderMissing
+		return nil, err
 	}
 	if ver == nil {
 		return nil, errNoVersioner
@@ -2332,16 +2334,13 @@ func (m *model) GetFolderVersions(folder string) (map[string][]versioner.FileVer
 }
 
 func (m *model) RestoreFolderVersions(folder string, versions map[string]time.Time) (map[string]string, error) {
-	fcfg, ok := m.cfg.Folder(folder)
-	if !ok {
-		return nil, errFolderMissing
-	}
-
 	m.fmut.RLock()
+	err := m.checkFolderRunningLocked(folder)
+	fcfg := m.folderCfgs[folder]
 	ver := m.folderVersioners[folder]
 	m.fmut.RUnlock()
-	if !ok {
+	if err != nil {
-		return nil, errFolderMissing
+		return nil, err
 	}
 	if ver == nil {
 		return nil, errNoVersioner

lib/model/model_test.go

@@ -3479,3 +3479,35 @@ func TestNewLimitedRequestResponse(t *testing.T) {
 		t.Error("Bytes weren't returned in a timely fashion")
 	}
 }
+
+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)
+		}
+	}
+}