lib/model: Send indexes for newly shared folder (fixes #7098) (#7100)

lib/model/model.go

@@ -478,18 +478,10 @@ func (m *model) restartFolder(from, to config.FolderConfiguration, cacheIgnoredF
 
 	// Cache the (maybe) existing fset before it's removed by cleanupFolderLocked
 	fset := m.folderFiles[folder]
+	fsetNil := fset == nil
 
 	m.cleanupFolderLocked(from)
-	if to.Paused {
-		// Care needs to be taken because we already hold fmut and the lock order
-		// must be the same everywhere. As fmut is acquired first, this is fine.
-		m.pmut.RLock()
-		for _, r := range m.indexSenders {
-			r.pause(to.ID)
-		}
-		m.pmut.RUnlock()
-	} else {
-		fsetNil := fset == nil
+	if !to.Paused {
 		if fsetNil {
 			// Create a new fset. Might take a while and we do it under
 			// locking, but it's unsafe to create fset:s concurrently so
@@ -497,16 +489,31 @@ func (m *model) restartFolder(from, to config.FolderConfiguration, cacheIgnoredF
 			fset = db.NewFileSet(folder, to.Filesystem(), m.db)
 		}
 		m.addAndStartFolderLocked(to, fset, cacheIgnoredFiles)
-		if fsetNil || from.Paused {
-			for _, devID := range to.DeviceIDs() {
-				indexSenders, ok := m.indexSenders[devID]
-				if !ok {
-					continue
-				}
-				indexSenders.resume(to, fset)
-			}
+	}
+
+	// Care needs to be taken because we already hold fmut and the lock order
+	// must be the same everywhere. As fmut is acquired first, this is fine.
+	// toDeviceIDs := to.DeviceIDs()
+	m.pmut.RLock()
+	for _, id := range to.DeviceIDs() {
+		indexSenders, ok := m.indexSenders[id]
+		if !ok {
+			continue
+		}
+		// In case the folder was newly shared with us we already got a
+		// cluster config and wont necessarily get another soon - start
+		// sending indexes if connected.
+		isNew := !from.SharedWith(indexSenders.deviceID)
+		if isNew {
+			indexSenders.addNew(to, fset)
+		}
+		if to.Paused {
+			indexSenders.pause(to.ID)
+		} else if !isNew && (fsetNil || from.Paused) {
+			indexSenders.resume(to, fset)
 		}
 	}
+	m.pmut.RUnlock()
 
 	var infoMsg string
 	switch {
@@ -527,7 +534,24 @@ func (m *model) newFolder(cfg config.FolderConfiguration, cacheIgnoredFiles bool
 
 	m.fmut.Lock()
 	defer m.fmut.Unlock()
+
+	// In case this folder is new and was shared with us we already got a
+	// cluster config and wont necessarily get another soon - start sending
+	// indexes if connected.
+	if fset.Sequence(protocol.LocalDeviceID) == 0 {
+		m.pmut.RLock()
+		for _, id := range cfg.DeviceIDs() {
+			if is, ok := m.indexSenders[id]; ok {
+				if fset.Sequence(id) == 0 {
+					is.addNew(cfg, fset)
+				}
+			}
+		}
+		m.pmut.RUnlock()
+	}
+
 	m.addAndStartFolderLocked(cfg, fset, cacheIgnoredFiles)
+
 }
 
 func (m *model) UsageReportingStats(report *contract.Report, version int, preview bool) {
@@ -1060,25 +1084,22 @@ func (m *model) ClusterConfig(deviceID protocol.DeviceID, cm protocol.ClusterCon
 			continue
 		}
 
-		var foundRemote, foundLocal bool
-		var remoteDeviceInfo, localDeviceInfo protocol.Device
+		deviceInfos := &indexSenderStartInfo{}
 		for _, dev := range folder.Devices {
 			if dev.ID == m.id {
-				localDeviceInfo = dev
-				foundLocal = true
+				deviceInfos.local = dev
 			} else if dev.ID == deviceID {
-				remoteDeviceInfo = dev
-				foundRemote = true
+				deviceInfos.remote = dev
 			}
-			if foundRemote && foundLocal {
+			if deviceInfos.local.ID != protocol.EmptyDeviceID && deviceInfos.remote.ID != protocol.EmptyDeviceID {
 				break
 			}
 		}
-		if !foundRemote {
+		if deviceInfos.remote.ID == protocol.EmptyDeviceID {
 			l.Infof("Device %v sent cluster-config without the device info for the remote on folder %v", deviceID, folder.Description())
 			return errMissingRemoteInClusterConfig
 		}
-		if !foundLocal {
+		if deviceInfos.local.ID == protocol.EmptyDeviceID {
 			l.Infof("Device %v sent cluster-config without the device info for us locally on folder %v", deviceID, folder.Description())
 			return errMissingLocalInClusterConfig
 		}
@@ -1090,10 +1111,7 @@ func (m *model) ClusterConfig(deviceID protocol.DeviceID, cm protocol.ClusterCon
 		}
 
 		if cfg.Paused {
-			indexSenderRegistry.addPaused(cfg, &indexSenderStartInfo{
-				local:  localDeviceInfo,
-				remote: remoteDeviceInfo,
-			})
+			indexSenderRegistry.addPaused(cfg, deviceInfos)
 			continue
 		}
 
@@ -1110,10 +1128,7 @@ func (m *model) ClusterConfig(deviceID protocol.DeviceID, cm protocol.ClusterCon
 			tempIndexFolders = append(tempIndexFolders, folder.ID)
 		}
 
-		indexSenderRegistry.add(cfg, fs, &indexSenderStartInfo{
-			local:  localDeviceInfo,
-			remote: remoteDeviceInfo,
-		})
+		indexSenderRegistry.add(cfg, fs, deviceInfos)
 
 		// We might already have files that we need to pull so let the
 		// folder runner know that it should recheck the index data.