cmd/syncthing: Do not truncate/rotate logs at start (#6359)

cmd/syncthing/monitor_test.go

@@ -33,7 +33,10 @@ func TestRotatedFile(t *testing.T) {
 	maxSize := int64(len(testData) + len(testData)/2)
 
 	// We allow the log file plus two rotated copies.
-	rf := newRotatedFile(logName, open, maxSize, 2)
+	rf, err := newRotatedFile(logName, open, maxSize, 2)
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	// Write some bytes.
 	if _, err := rf.Write(testData); err != nil {
@@ -140,7 +143,10 @@ func TestAutoClosedFile(t *testing.T) {
 	data := []byte("hello, world\n")
 
 	// An autoclosed file that closes very quickly
-	ac := newAutoclosedFile(file, time.Millisecond, time.Millisecond)
+	ac, err := newAutoclosedFile(file, time.Millisecond, time.Millisecond)
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	// Write some data.
 	if _, err := ac.Write(data); err != nil {
@@ -182,21 +188,23 @@ func TestAutoClosedFile(t *testing.T) {
 	}
 
 	// Open the file again.
-	ac = newAutoclosedFile(file, time.Second, time.Second)
+	ac, err = newAutoclosedFile(file, time.Second, time.Second)
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	// Write something
 	if _, err := ac.Write(data); err != nil {
 		t.Fatal(err)
 	}
 
-	// It should now contain only one write, because the first open
-	// should be a truncate.
+	// It should now contain three writes, as the file is always opened for appending
 	bs, err = ioutil.ReadFile(file)
 	if err != nil {
 		t.Fatal(err)
 	}
-	if len(bs) != len(data) {
-		t.Fatalf("Write failed, expected %d bytes, not %d", len(data), len(bs))
+	if len(bs) != 3*len(data) {
+		t.Fatalf("Write failed, expected %d bytes, not %d", 3*len(data), len(bs))
 	}
 
 	// Close.