Fix restoring files as non-root user

As we cannot reliably detect in advance if we can set ownership, permissions,
timestamps or ext attributes, execute ALL the requested changes before
returning the first error we found.

Report total errors at end of restore and stop printing entire stacktraces
where just the error message is sufficient.

Fixes #655

src/cmds/restic/cmd_restore.go

@@ -103,8 +103,10 @@ func runRestore(opts RestoreOptions, gopts GlobalOptions, args []string) error {
 		Exitf(2, "creating restorer failed: %v\n", err)
 	}
 
+	totalErrors := 0
 	res.Error = func(dir string, node *restic.Node, err error) error {
-		Warnf("error for %s: %+v\n", dir, err)
+		Warnf("ignoring error for %s: %s\n", dir, err)
+		totalErrors++
 		return nil
 	}
 
@@ -134,5 +136,9 @@ func runRestore(opts RestoreOptions, gopts GlobalOptions, args []string) error {
 
 	Verbosef("restoring %s to %s\n", res.Snapshot(), opts.Target)
 
-	return res.RestoreTo(opts.Target)
+	err = res.RestoreTo(opts.Target)
+	if totalErrors > 0 {
+		Printf("There were %d errors\n", totalErrors)
+	}
+	return err
 }

src/restic/node.go

@@ -158,35 +158,37 @@ func (node *Node) CreateAt(path string, repo Repository, idx *HardlinkIndex) err
 }
 
 func (node Node) restoreMetadata(path string) error {
-	var err error
+	var firsterr error
 
-	err = lchown(path, int(node.UID), int(node.GID))
-	if err != nil {
-		return errors.Wrap(err, "Lchown")
+	if err := lchown(path, int(node.UID), int(node.GID)); err != nil {
+		firsterr = errors.Wrap(err, "Lchown")
 	}
 
 	if node.Type != "symlink" {
-		err = fs.Chmod(path, node.Mode)
-		if err != nil {
-			return errors.Wrap(err, "Chmod")
+		if err := fs.Chmod(path, node.Mode); err != nil {
+			if firsterr != nil {
+				firsterr = errors.Wrap(err, "Chmod")
+			}
 		}
 	}
 
 	if node.Type != "dir" {
-		err = node.RestoreTimestamps(path)
-		if err != nil {
+		if err := node.RestoreTimestamps(path); err != nil {
 			debug.Log("error restoring timestamps for dir %v: %v", path, err)
-			return err
+			if firsterr != nil {
+				firsterr = err
+			}
 		}
 	}
 
-	err = node.restoreExtendedAttributes(path)
-	if err != nil {
+	if err := node.restoreExtendedAttributes(path); err != nil {
 		debug.Log("error restoring extended attributes for %v: %v", path, err)
-		return err
+		if firsterr != nil {
+			firsterr = err
+		}
 	}
 
-	return nil
+	return firsterr
 }
 
 func (node Node) restoreExtendedAttributes(path string) error {