gst/gstinfo.h: do not crash on pad==NULL

Original commit message from CVS:
* gst/gstinfo.h:
do not crash on pad==NULL

ChangeLog

+2005-11-24  Stefan Kost  <ensonic@users.sf.net>
+
+	* gst/gstinfo.h:
+	  do not crash on pad==NULL
+
 2005-11-24  Thomas Vander Stichele  <thomas at apestaart dot org>
 
 	Patch by: Stefan Kost

gst/gstinfo.h

@@ -185,9 +185,11 @@ struct _GstDebugCategory {
  * statements.
  */
 #define GST_DEBUG_PAD_NAME(pad) \
-  (GST_OBJECT_PARENT(pad) != NULL) ? \
+  (pad != NULL) ?  \
+  ((GST_OBJECT_PARENT(pad) != NULL) ? \
   GST_STR_NULL (GST_OBJECT_NAME (GST_OBJECT_PARENT(pad))) : \
-  "''", GST_OBJECT_NAME (pad)
+  "''" ) : "''", \
+  (pad==NULL) ? GST_OBJECT_NAME (pad) : "''"
 
 /**
  * GST_FUNCTION: