From bd90dcd000bbc315b26153f091ce6a2ac592f1d7 Mon Sep 17 00:00:00 2001
From: "Kim F. Storm" <storm@cua.dk>
Date: Wed, 9 Nov 2005 23:14:32 +0000
Subject: [PATCH] (safe_debug_print): New function to be called from gdb to
 print Lisp objects; use valid_lisp_object_p to avoid crashing if user tries
 to print something which is not a Lisp object.

---
 src/print.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/print.c b/src/print.c
index 91642afd651..d563580ddd3 100644
--- a/src/print.c
+++ b/src/print.c
@@ -970,6 +970,26 @@ debug_print (arg)
   Fprin1 (arg, Qexternal_debugging_output);
   fprintf (stderr, "\r\n");
 }
+
+void
+safe_debug_print (arg)
+     Lisp_Object arg;
+{
+  int valid = valid_lisp_object_p (arg);
+
+  if (valid > 0)
+    debug_print (arg);
+  else
+    fprintf (stderr, "#<%s_LISP_OBJECT 0x%08lx>\r\n",
+	     !valid ? "INVALID" : "SOME",
+#ifdef NO_UNION_TYPE
+	     (unsigned long) arg
+#else
+	     (unsigned long) arg.i
+#endif
+	     );
+}
+
 
 DEFUN ("error-message-string", Ferror_message_string, Serror_message_string,
        1, 1, 0,
-- 
2.39.2