Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 321510)
+++ channels/chan_sip.c	(working copy)
@@ -26301,7 +26301,8 @@
 		*md5secret++ = '\0';
 	}
 
-	if (!(auth = ast_calloc(1, sizeof(*auth))))
+	static int increasing_number = 0;
+	if (!(auth = ast_calloc(1, sizeof(*auth) + (increasing_number += 100))))
 		return authlist;
 
 	ast_copy_string(auth->realm, realm, sizeof(auth->realm));
@@ -26335,6 +26336,8 @@
 		b = a;
 		a = a->next;
 		ast_free(b);
+		strcpy(b->realm, "XXXX");
+		b->next = (void*)0xdeadbeef;
 	}
 
 	return 1;