lib/config: Prevent nil deref in debug logging (fixes #5955) (#5956)

lib/api/mocked_connections_test.go

@@ -27,3 +27,7 @@ func (m *mockedConnections) NATType() string {
 func (m *mockedConnections) Serve() {}
 
 func (m *mockedConnections) Stop() {}
+
+func (m *mockedConnections) ExternalAddresses() []string { return nil }
+
+func (m *mockedConnections) AllAddresses() []string { return nil }

lib/config/folderconfiguration.go

@@ -248,9 +248,12 @@ func (f *FolderConfiguration) prepare() {
 	case f.RawModTimeWindowS > 0:
 		f.cachedModTimeWindow = time.Duration(f.RawModTimeWindowS) * time.Second
 	case runtime.GOOS == "android":
-		if usage, err := disk.Usage(f.Filesystem().URI()); err != nil || usage.Fstype == "" || strings.Contains(strings.ToLower(usage.Fstype), "fat") {
+		if usage, err := disk.Usage(f.Filesystem().URI()); err != nil {
 			f.cachedModTimeWindow = 2 * time.Second
-			l.Debugf(`Detecting FS at %v on android: Setting mtime window to 2s: err == %v, usage.Fstype == "%v"`, f.Path, err, usage.Fstype)
+			l.Debugf(`Detecting FS at "%v" on android: Setting mtime window to 2s: err == "%v"`, f.Path, err)
+		} else if usage.Fstype == "" || strings.Contains(strings.ToLower(usage.Fstype), "fat") {
+			f.cachedModTimeWindow = 2 * time.Second
+			l.Debugf(`Detecting FS at "%v" on android: Setting mtime window to 2s: usage.Fstype == "%v"`, f.Path, usage.Fstype)
 		} else {
 			l.Debugf(`Detecting FS at %v on android: Leaving mtime window at 0: usage.Fstype == "%v"`, f.Path, usage.Fstype)
 		}

lib/connections/service.go

@@ -90,6 +90,7 @@ var tlsVersionNames = map[uint16]string{
 // dialers. Successful connections are handed to the model.
 type Service interface {
 	suture.Service
+	discover.AddressLister
 	ListenerStatus() map[string]ListenerStatusEntry
 	ConnectionStatus() map[string]ConnectionStatusEntry
 	NATType() string
@@ -129,9 +130,7 @@ type service struct {
 	connectionStatus    map[string]ConnectionStatusEntry // address -> latest error/status
 }
 
-func NewService(cfg config.Wrapper, myID protocol.DeviceID, mdl Model, tlsCfg *tls.Config, discoverer discover.Finder,
-	bepProtocolName string, tlsDefaultCommonName string) *service {
-
+func NewService(cfg config.Wrapper, myID protocol.DeviceID, mdl Model, tlsCfg *tls.Config, discoverer discover.Finder, bepProtocolName string, tlsDefaultCommonName string) Service {
 	service := &service{
 		Supervisor: suture.New("connections.Service", suture.Spec{
 			Log: func(line string) {

lib/model/folder.go

@@ -685,10 +685,11 @@ func (f *folder) setWatchError(err error) {
 // scanOnWatchErr schedules a full scan immediately if an error occurred while watching.
 func (f *folder) scanOnWatchErr() {
 	f.watchMut.Lock()
-	if f.watchErr != nil {
+	err := f.watchErr
+	f.watchMut.Unlock()
+	if err != nil {
 		f.Delay(0)
 	}
-	f.watchMut.Unlock()
 }
 
 func (f *folder) setError(err error) {

lib/model/model.go

@@ -765,8 +765,9 @@ func addSizeOfFile(s *db.Counts, f db.FileIntf) {
 // files in the global model.
 func (m *model) GlobalSize(folder string) db.Counts {
 	m.fmut.RLock()
-	defer m.fmut.RUnlock()
-	if rf, ok := m.folderFiles[folder]; ok {
+	rf, ok := m.folderFiles[folder]
+	m.fmut.RUnlock()
+	if ok {
 		return rf.GlobalSize()
 	}
 	return db.Counts{}
@@ -776,8 +777,9 @@ func (m *model) GlobalSize(folder string) db.Counts {
 // files in the local folder.
 func (m *model) LocalSize(folder string) db.Counts {
 	m.fmut.RLock()
-	defer m.fmut.RUnlock()
-	if rf, ok := m.folderFiles[folder]; ok {
+	rf, ok := m.folderFiles[folder]
+	m.fmut.RUnlock()
+	if ok {
 		return rf.LocalSize()
 	}
 	return db.Counts{}
@@ -788,8 +790,9 @@ func (m *model) LocalSize(folder string) db.Counts {
 // folder.
 func (m *model) ReceiveOnlyChangedSize(folder string) db.Counts {
 	m.fmut.RLock()
-	defer m.fmut.RUnlock()
-	if rf, ok := m.folderFiles[folder]; ok {
+	rf, ok := m.folderFiles[folder]
+	m.fmut.RUnlock()
+	if ok {
 		return rf.ReceiveOnlyChangedSize()
 	}
 	return db.Counts{}
@@ -1006,8 +1009,9 @@ func (m *model) handleIndex(deviceID protocol.DeviceID, folder string, fs []prot
 	}
 
 	m.pmut.RLock()
-	m.deviceDownloads[deviceID].Update(folder, makeForgetUpdate(fs))
+	downloads := m.deviceDownloads[deviceID]
 	m.pmut.RUnlock()
+	downloads.Update(folder, makeForgetUpdate(fs))
 
 	if !update {
 		files.Drop(deviceID)
@@ -1885,9 +1889,10 @@ func (m *model) DownloadProgress(device protocol.DeviceID, folder string, update
 	}
 
 	m.pmut.RLock()
-	m.deviceDownloads[device].Update(folder, updates)
-	state := m.deviceDownloads[device].GetBlockCounts(folder)
+	downloads := m.deviceDownloads[device]
 	m.pmut.RUnlock()
+	downloads.Update(folder, updates)
+	state := downloads.GetBlockCounts(folder)
 
 	events.Default.Log(events.RemoteDownloadProgress, map[string]interface{}{
 		"device": device.String(),
@@ -2227,20 +2232,24 @@ func (m *model) State(folder string) (string, time.Time, error) {
 
 func (m *model) FolderErrors(folder string) ([]FileError, error) {
 	m.fmut.RLock()
-	defer m.fmut.RUnlock()
-	if err := m.checkFolderRunningLocked(folder); err != nil {
+	err := m.checkFolderRunningLocked(folder)
+	runner := m.folderRunners[folder]
+	m.fmut.RUnlock()
+	if err != nil {
 		return nil, err
 	}
-	return m.folderRunners[folder].Errors(), nil
+	return runner.Errors(), nil
 }
 
 func (m *model) WatchError(folder string) error {
 	m.fmut.RLock()
-	defer m.fmut.RUnlock()
-	if err := m.checkFolderRunningLocked(folder); err != nil {
+	err := m.checkFolderRunningLocked(folder)
+	runner := m.folderRunners[folder]
+	m.fmut.RUnlock()
+	if err != nil {
 		return nil // If the folder isn't running, there's no error to report.
 	}
-	return m.folderRunners[folder].WatchError()
+	return runner.WatchError()
 }
 
 func (m *model) Override(folder string) {