* src/frame.c (make_monitor_attribute_list): Allow source to be NULL.

diff --git a/src/frame.c b/src/frame.c
index 36a256f1f3df38ad0965f8a8f2dadb8d6fb8bc45..286c9a2cb71fcfbcf70114cbedeac6a8aecb3b78 100644 (file)
--- a/src/frame.c
+++ b/src/frame.c
@@ -6138,8 +6138,11 @@ make_monitor_attribute_list (struct MonitorInfo *monitors,
                         mi->work.width, mi->work.height);
       geometry = list4i (mi->geom.x, mi->geom.y,
                         mi->geom.width, mi->geom.height);
-      attributes = Fcons (Fcons (Qsource, build_string (source)),
-                          attributes);
+
+      if (source)
+       attributes = Fcons (Fcons (Qsource, build_string (source)),
+                           attributes);
+
       attributes = Fcons (Fcons (Qframes, AREF (monitor_frames, i)),
                          attributes);
 #ifdef HAVE_PGTK