lib/db, lib/model: Resolve identical recv only items (fixes #5130) (#5230)

lib/model/folder_recvonly_test.go

@@ -196,8 +196,8 @@ func TestRecvOnlyRevertNeeds(t *testing.T) {
 
 	size = m.GlobalSize("ro")
 	const sizeOfDir = 128
-	if size.Files != 1 || size.Bytes != sizeOfDir+int64(len(newData)) {
-		t.Fatalf("Global: expected the new file to be reflected: %+v", size)
+	if size.Files != 1 || size.Bytes != sizeOfDir+int64(len(oldData)) {
+		t.Fatalf("Global: expected no change due to the new file: %+v", size)
 	}
 	size = m.LocalSize("ro")
 	if size.Files != 1 || size.Bytes != sizeOfDir+int64(len(newData)) {
@@ -230,6 +230,99 @@ func TestRecvOnlyRevertNeeds(t *testing.T) {
 	}
 }
 
+func TestRecvOnlyUndoChanges(t *testing.T) {
+	if err := os.RemoveAll("_recvonly"); err != nil && !os.IsNotExist(err) {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := os.RemoveAll("_recvonly"); err != nil && !os.IsNotExist(err) {
+			t.Fatal(err)
+		}
+	}()
+
+	// Create some test data
+
+	if err := os.MkdirAll("_recvonly/.stfolder", 0755); err != nil {
+		t.Fatal(err)
+	}
+	oldData := []byte("hello\n")
+	knownFiles := setupKnownFiles(t, oldData)
+
+	// Get us a model up and running
+
+	m := setupROFolder()
+	defer m.Stop()
+
+	m.fmut.Lock()
+	fset := m.folderFiles["ro"]
+	m.fmut.Unlock()
+	folderFs := fset.MtimeFS()
+
+	// Send and index update for the known stuff
+
+	m.Index(device1, "ro", knownFiles)
+	m.updateLocalsFromScanning("ro", knownFiles)
+
+	// Start the folder. This will cause a scan.
+
+	m.StartFolder("ro")
+	m.ScanFolder("ro")
+
+	// Everything should be in sync.
+
+	size := m.GlobalSize("ro")
+	if size.Files != 1 || size.Directories != 1 {
+		t.Fatalf("Global: expected 1 file and 1 directory: %+v", size)
+	}
+	size = m.LocalSize("ro")
+	if size.Files != 1 || size.Directories != 1 {
+		t.Fatalf("Local: expected 1 file and 1 directory: %+v", size)
+	}
+	size = m.NeedSize("ro")
+	if size.Files+size.Directories > 0 {
+		t.Fatalf("Need: expected nothing: %+v", size)
+	}
+	size = m.ReceiveOnlyChangedSize("ro")
+	if size.Files+size.Directories > 0 {
+		t.Fatalf("ROChanged: expected nothing: %+v", size)
+	}
+
+	// Create a file and modify another
+
+	file := "_recvonly/foo"
+	if err := ioutil.WriteFile(file, []byte("hello\n"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := ioutil.WriteFile("_recvonly/knownDir/knownFile", []byte("bye\n"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	m.ScanFolder("ro")
+
+	size = m.ReceiveOnlyChangedSize("ro")
+	if size.Files != 2 {
+		t.Fatalf("Receive only: expected 2 files: %+v", size)
+	}
+
+	// Remove the file again and undo the modification
+
+	if err := os.Remove(file); err != nil {
+		t.Fatal(err)
+	}
+	if err := ioutil.WriteFile("_recvonly/knownDir/knownFile", oldData, 0644); err != nil {
+		t.Fatal(err)
+	}
+	folderFs.Chtimes("knownDir/knownFile", knownFiles[1].ModTime(), knownFiles[1].ModTime())
+
+	m.ScanFolder("ro")
+
+	size = m.ReceiveOnlyChangedSize("ro")
+	if size.Files+size.Directories+size.Deleted != 0 {
+		t.Fatalf("Receive only: expected all zero: %+v", size)
+	}
+}
+
 func setupKnownFiles(t *testing.T, data []byte) []protocol.FileInfo {
 	if err := os.MkdirAll("_recvonly/knownDir", 0755); err != nil {
 		t.Fatal(err)

lib/model/model.go

@@ -2058,14 +2058,38 @@ func (m *Model) internalScanFolderSubdirs(ctx context.Context, folder string, su
 		return err
 	}
 
-	batch := newFileInfoBatch(func(fs []protocol.FileInfo) error {
+	batchFn := func(fs []protocol.FileInfo) error {
 		if err := runner.CheckHealth(); err != nil {
 			l.Debugf("Stopping scan of folder %s due to: %s", folderCfg.Description(), err)
 			return err
 		}
 		m.updateLocalsFromScanning(folder, fs)
 		return nil
-	})
+	}
+	// Resolve items which are identical with the global state.
+	if localFlags&protocol.FlagLocalReceiveOnly != 0 {
+		oldBatchFn := batchFn // can't reference batchFn directly (recursion)
+		batchFn = func(fs []protocol.FileInfo) error {
+			for i := range fs {
+				switch gf, ok := fset.GetGlobal(fs[i].Name); {
+				case !ok:
+					continue
+				case gf.IsEquivalentOptional(fs[i], false, false, protocol.FlagLocalReceiveOnly):
+					// What we have locally is equivalent to the global file.
+					fs[i].Version = fs[i].Version.Merge(gf.Version)
+					fallthrough
+				case fs[i].IsDeleted() && gf.IsReceiveOnlyChanged():
+					// Our item is deleted and the global item is our own
+					// receive only file. We can't delete file infos, so
+					// we just pretend it is a normal deleted file (nobody
+					// cares about that).
+					fs[i].LocalFlags &^= protocol.FlagLocalReceiveOnly
+				}
+			}
+			return oldBatchFn(fs)
+		}
+	}
+	batch := newFileInfoBatch(batchFn)
 
 	// Schedule a pull after scanning, but only if we actually detected any
 	// changes.