Fix ModTime for directories

cmd/dirdiff/main.go

@@ -62,7 +62,8 @@ func (e *entry) equals(other *entry) bool {
 
 	if e.fi.ModTime() != other.fi.ModTime() {
 		fmt.Printf("%s: ModTime does not match\n", e.path)
-		// TODO: Fix ModTime for directories, return false
+		// TODO: Fix ModTime for symlinks, return false
+		// see http://grokbase.com/t/gg/golang-nuts/154wnph4y8/go-nuts-no-way-to-utimes-a-symlink
 		return true
 	}
 

node.go

@@ -155,12 +155,23 @@ func (node Node) restoreMetadata(path string) error {
 		return errors.Annotate(err, "Chmod")
 	}
 
+	if node.Type != "dir" {
+		err = node.RestoreTimestamps(path)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (node Node) RestoreTimestamps(path string) error {
 	var utimes = []syscall.Timespec{
 		syscall.NsecToTimespec(node.AccessTime.UnixNano()),
 		syscall.NsecToTimespec(node.ModTime.UnixNano()),
 	}
-	err = syscall.UtimesNano(path, utimes)
-	if err != nil {
+
+	if err := syscall.UtimesNano(path, utimes); err != nil {
 		return errors.Annotate(err, "UtimesNano")
 	}
 

restorer.go

@@ -64,6 +64,18 @@ func (res *Restorer) restoreTo(dst string, dir string, treeID backend.ID) error
 		}
 	}
 
+	// Restore directory timestamps at the end. If we would do it earlier, restoring files within
+	// those directories would overwrite the timestamp of the directories they are in.
+	for _, node := range tree.Nodes {
+		if node.Type != "dir" {
+			continue
+		}
+
+		if err := node.RestoreTimestamps(filepath.Join(dst, dir, node.Name)); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }