GDataInputStream: don't segfault on async line reads

If an async line read fails, it returns NULL. In that case, we
must return NULL before validating the line, or we segfault.

https://bugzilla.gnome.org/show_bug.cgi?id=658484

diff --git a/gio/gdatainputstream.c b/gio/gdatainputstream.c
index d5dd2fd..ea26aeb 100644 (file)
--- a/gio/gdatainputstream.c
+++ b/gio/gdatainputstream.c
@@ -1284,6 +1284,9 @@ g_data_input_stream_read_line_finish_utf8 (GDataInputStream  *stream,
   gchar *res;
 
   res = g_data_input_stream_read_line_finish (stream, result, length, error);
+  if (!res)
+    return NULL;
+
   if (!g_utf8_validate (res, -1, NULL))
     {
       g_set_error_literal (error, G_CONVERT_ERROR,