Fix folder check tests

cmd/syncthing/main_test.go

@@ -20,6 +20,10 @@ import (
 )
 
 func TestFolderErrors(t *testing.T) {
+	// This test intentionally avoids starting the folders. If they are
+	// started, they will perform an initial scan, which will create missing
+	// folder markers and race with the stuff we do in the test.
+
 	fcfg := config.FolderConfiguration{
 		ID:      "folder",
 		RawPath: "testdata/testfolder",
@@ -29,10 +33,8 @@ func TestFolderErrors(t *testing.T) {
 	})
 
 	for _, file := range []string{".stfolder", "testfolder/.stfolder", "testfolder"} {
-		os.Remove("testdata/" + file)
+		if err := os.Remove("testdata/" + file); err != nil && !os.IsNotExist(err) {
-		_, err := os.Stat("testdata/" + file)
+			t.Fatal(err)
-		if err == nil {
-			t.Error("Found unexpected file")
 		}
 	}
 
@@ -42,7 +44,6 @@ func TestFolderErrors(t *testing.T) {
 
 	m := model.NewModel(cfg, protocol.LocalDeviceID, "device", "syncthing", "dev", ldb)
 	m.AddFolder(fcfg)
-	m.StartFolderRW("folder")
 
 	if err := m.CheckFolderHealth("folder"); err != nil {
 		t.Error("Unexpected error", cfg.Folders()["folder"].Invalid)
@@ -58,8 +59,12 @@ func TestFolderErrors(t *testing.T) {
 		t.Error(err)
 	}
 
-	os.Remove("testdata/testfolder/.stfolder")
+	if err := os.Remove("testdata/testfolder/.stfolder"); err != nil {
-	os.Remove("testdata/testfolder/")
+		t.Fatal(err)
+	}
+	if err := os.Remove("testdata/testfolder/"); err != nil {
+		t.Fatal(err)
+	}
 
 	// Case 2 - new folder, marker created
 
@@ -70,7 +75,6 @@ func TestFolderErrors(t *testing.T) {
 
 	m = model.NewModel(cfg, protocol.LocalDeviceID, "device", "syncthing", "dev", ldb)
 	m.AddFolder(fcfg)
-	m.StartFolderRW("folder")
 
 	if err := m.CheckFolderHealth("folder"); err != nil {
 		t.Error("Unexpected error", cfg.Folders()["folder"].Invalid)
@@ -81,7 +85,9 @@ func TestFolderErrors(t *testing.T) {
 		t.Error(err)
 	}
 
-	os.Remove("testdata/.stfolder")
+	if err := os.Remove("testdata/.stfolder"); err != nil {
+		t.Fatal(err)
+	}
 
 	// Case 3 - Folder marker missing
 
@@ -92,7 +98,6 @@ func TestFolderErrors(t *testing.T) {
 
 	m = model.NewModel(cfg, protocol.LocalDeviceID, "device", "syncthing", "dev", ldb)
 	m.AddFolder(fcfg)
-	m.StartFolderRW("folder")
 
 	if err := m.CheckFolderHealth("folder"); err == nil || err.Error() != "folder marker missing" {
 		t.Error("Incorrect error: Folder marker missing !=", m.CheckFolderHealth("folder"))
@@ -110,8 +115,12 @@ func TestFolderErrors(t *testing.T) {
 
 	// Case 4 - Folder path missing
 
-	os.Remove("testdata/testfolder/.stfolder")
+	if err := os.Remove("testdata/testfolder/.stfolder"); err != nil && !os.IsNotExist(err) {
-	os.Remove("testdata/testfolder/")
+		t.Fatal(err)
+	}
+	if err := os.Remove("testdata/testfolder"); err != nil && !os.IsNotExist(err) {
+		t.Fatal(err)
+	}
 
 	fcfg.RawPath = "testdata/testfolder"
 	cfg = config.Wrap("testdata/subfolder", config.Configuration{
@@ -120,7 +129,6 @@ func TestFolderErrors(t *testing.T) {
 
 	m = model.NewModel(cfg, protocol.LocalDeviceID, "device", "syncthing", "dev", ldb)
 	m.AddFolder(fcfg)
-	m.StartFolderRW("folder")
 
 	if err := m.CheckFolderHealth("folder"); err == nil || err.Error() != "folder path missing" {
 		t.Error("Incorrect error: Folder path missing !=", m.CheckFolderHealth("folder"))
@@ -128,7 +136,9 @@ func TestFolderErrors(t *testing.T) {
 
 	// Case 4.1 - recover after folder path missing
 
-	os.Mkdir("testdata/testfolder", 0700)
+	if err := os.Mkdir("testdata/testfolder", 0700); err != nil {
+		t.Fatal(err)
+	}
 
 	if err := m.CheckFolderHealth("folder"); err == nil || err.Error() != "folder marker missing" {
 		t.Error("Incorrect error: Folder marker missing !=", m.CheckFolderHealth("folder"))

internal/model/model.go

@@ -1565,9 +1565,13 @@ func (m *Model) CheckFolderHealth(id string) error {
 	}
 
 	m.fmut.RLock()
-	runner := m.folderRunners[folder.ID]
+	runner, runnerExists := m.folderRunners[folder.ID]
 	m.fmut.RUnlock()
-	_, _, oldErr := runner.getState()
+
+	var oldErr error
+	if runnerExists {
+		_, _, oldErr = runner.getState()
+	}
 
 	if err != nil {
 		if oldErr != nil && oldErr.Error() != err.Error() {
@@ -1575,11 +1579,15 @@ func (m *Model) CheckFolderHealth(id string) error {
 		} else if oldErr == nil {
 			l.Warnf("Stopping folder %q - %v", folder.ID, err)
 		}
+		if runnerExists {
 			runner.setError(err)
+		}
 	} else if oldErr != nil {
 		l.Infof("Folder %q error is cleared, restarting", folder.ID)
+		if runnerExists {
 			runner.setState(FolderIdle)
 		}
+	}
 
 	return err
 }

internal/model/rwfolder.go

@@ -121,6 +121,11 @@ func (p *rwFolder) Serve() {
 	var prevIgnoreHash string
 
 	rescheduleScan := func() {
+		if p.scanIntv == 0 {
+			// We should not run scans, so it should not be rescheduled.
+			return
+		}
+
 		// Sleep a random time between 3/4 and 5/4 of the configured interval.
 		sleepNanos := (p.scanIntv.Nanoseconds()*3 + rand.Int63n(2*p.scanIntv.Nanoseconds())) / 4
 		intv := time.Duration(sleepNanos) * time.Nanosecond