Fix compilation with GC_MARK_STACK == GC_USE_GCPROS_AS_BEFORE.

* eval.c (eval_sub): Protect `form' from being GCed before its
car and cdr becomes protected with the backtrace entry.

2 files changed, 9 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 098d3ae027e..2445027edd5 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,11 @@
 2013-01-14  Dmitry Antipov  <dmantipov@yandex.ru>
 
+        Fix compilation with GC_MARK_STACK == GC_USE_GCPROS_AS_BEFORE.
+        * eval.c (eval_sub): Protect `form' from being GCed before its
+        car and cdr becomes protected with the backtrace entry.
+
+2013-01-14  Dmitry Antipov  <dmantipov@yandex.ru>
+
         Make Lisp_Save_Value more versatile storage for up to four objects.
         * lisp.h (toplevel): Enumeration to describe types of saved objects.
         (struct Lisp_Save_Value): New layout.  Adjust comments.
diff --git a/src/eval.c b/src/eval.c
index c49f8e85c2f..030bf14bcea 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1931,7 +1931,10 @@ eval_sub (Lisp_Object form)
     return form;
 
   QUIT;
+
+  GCPRO1 (form);
   maybe_gc ();
+  UNGCPRO;
 
   if (++lisp_eval_depth > max_lisp_eval_depth)
     {