Save files in local storage as umask (#21198)

Go creates temporary files as 600, but sometimes we want the group to be able to read them (for example,
for another user to back up the storage)

This PR applies the umask to the renamed tmp files in local storage.

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/storage/local.go

@@ -102,6 +102,10 @@ func (l *LocalStorage) Save(path string, r io.Reader, size int64) (int64, error)
 	if err := util.Rename(tmp.Name(), p); err != nil {
 		return 0, err
 	}
+	// Golang's tmp file (os.CreateTemp) always have 0o600 mode, so we need to change the file to follow the umask (as what Create/MkDir does)
+	if err := util.ApplyUmask(p, os.ModePerm); err != nil {
+		return 0, err
+	}
 
 	tmpRemoved = true