Merge pull request #2253 from restic/fix-2174

Make sure timestamps are valid

changelog/unreleased/issue-2174

@@ -0,0 +1,10 @@
+Bugfix: Save files with invalid timestamps
+
+When restic reads invalid timestamps (year is before 0000 or after 9999) it
+refused to read and archive the file. We've changed the behavior and will now
+save modified timestamps with the year set to either 0000 or 9999, the rest of
+the timestamp stays the same, so the file will be saved (albeit with a bogus
+timestamp).
+
+https://github.com/restic/restic/issues/2174
+https://github.com/restic/restic/issues/1173

internal/restic/node.go

@@ -332,24 +332,27 @@ func (node *Node) createFifoAt(path string) error {
 	return mkfifo(path, 0600)
 }
 
+// FixTime returns a time.Time which can safely be used to marshal as JSON. If
+// the timestamp is ealier that year zero, the year is set to zero. In the same
+// way, if the year is larger than 9999, the year is set to 9999. Other than
+// the year nothing is changed.
+func FixTime(t time.Time) time.Time {
+	switch {
+	case t.Year() < 0000:
+		return t.AddDate(-t.Year(), 0, 0)
+	case t.Year() > 9999:
+		return t.AddDate(-(t.Year() - 9999), 0, 0)
+	default:
+		return t
+	}
+}
+
 func (node Node) MarshalJSON() ([]byte, error) {
-	if node.ModTime.Year() < 0 || node.ModTime.Year() > 9999 {
-		err := errors.Errorf("node %v has invalid ModTime year %d: %v",
-			node.Path, node.ModTime.Year(), node.ModTime)
-		return nil, err
-	}
-
-	if node.ChangeTime.Year() < 0 || node.ChangeTime.Year() > 9999 {
-		err := errors.Errorf("node %v has invalid ChangeTime year %d: %v",
-			node.Path, node.ChangeTime.Year(), node.ChangeTime)
-		return nil, err
-	}
-
-	if node.AccessTime.Year() < 0 || node.AccessTime.Year() > 9999 {
-		err := errors.Errorf("node %v has invalid AccessTime year %d: %v",
-			node.Path, node.AccessTime.Year(), node.AccessTime)
-		return nil, err
-	}
+	// make sure invalid timestamps for mtime and atime are converted to
+	// something we can actually save.
+	node.ModTime = FixTime(node.ModTime)
+	node.AccessTime = FixTime(node.AccessTime)
+	node.ChangeTime = FixTime(node.ChangeTime)
 
 	type nodeJSON Node
 	nj := nodeJSON(node)

internal/restic/node_test.go

@@ -244,3 +244,54 @@ func AssertFsTimeEqual(t *testing.T, label string, nodeType string, t1 time.Time
 
 	rtest.Assert(t, equal, "%s: %s doesn't match (%v != %v)", label, nodeType, t1, t2)
 }
+
+func parseTimeNano(t testing.TB, s string) time.Time {
+	// 2006-01-02T15:04:05.999999999Z07:00
+	ts, err := time.Parse(time.RFC3339Nano, s)
+	if err != nil {
+		t.Fatalf("error parsing %q: %v", s, err)
+	}
+	return ts
+}
+
+func TestFixTime(t *testing.T) {
+	// load UTC location
+	utc, err := time.LoadLocation("")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var tests = []struct {
+		src, want time.Time
+	}{
+		{
+			src:  parseTimeNano(t, "2006-01-02T15:04:05.999999999+07:00"),
+			want: parseTimeNano(t, "2006-01-02T15:04:05.999999999+07:00"),
+		},
+		{
+			src:  time.Date(0, 1, 2, 3, 4, 5, 6, utc),
+			want: parseTimeNano(t, "0000-01-02T03:04:05.000000006+00:00"),
+		},
+		{
+			src:  time.Date(-2, 1, 2, 3, 4, 5, 6, utc),
+			want: parseTimeNano(t, "0000-01-02T03:04:05.000000006+00:00"),
+		},
+		{
+			src:  time.Date(12345, 1, 2, 3, 4, 5, 6, utc),
+			want: parseTimeNano(t, "9999-01-02T03:04:05.000000006+00:00"),
+		},
+		{
+			src:  time.Date(9999, 1, 2, 3, 4, 5, 6, utc),
+			want: parseTimeNano(t, "9999-01-02T03:04:05.000000006+00:00"),
+		},
+	}
+
+	for _, test := range tests {
+		t.Run("", func(t *testing.T) {
+			res := restic.FixTime(test.src)
+			if !res.Equal(test.want) {
+				t.Fatalf("wrong result for %v, want:\n  %v\ngot:\n  %v", test.src, test.want, res)
+			}
+		})
+	}
+}