fuse/ipns: Only change file size in Setattr if asked to

This used to cause files e.g. being edited with `vi` to become 0-size.

License: MIT
Signed-off-by: Tommi Virtanen <tv@eagain.net>

fuse/ipns/ipns_unix.go

@@ -335,15 +335,17 @@ func (fi *File) Flush(ctx context.Context, req *fuse.FlushRequest) error {
 }
 
 func (fi *File) Setattr(ctx context.Context, req *fuse.SetattrRequest, resp *fuse.SetattrResponse) error {
-	cursize, err := fi.fi.Size()
-	if err != nil {
-		return err
-	}
-	if cursize != int64(req.Size) {
-		err := fi.fi.Truncate(int64(req.Size))
+	if req.Valid.Size() {
+		cursize, err := fi.fi.Size()
 		if err != nil {
 			return err
 		}
+		if cursize != int64(req.Size) {
+			err := fi.fi.Truncate(int64(req.Size))
+			if err != nil {
+				return err
+			}
+		}
 	}
 	return nil
 }