Fix crashes with lots of overlays.

 src/editfns.c (get_pos_property): Use SAFE_ALLOCA_LISP, to avoid
 segfault when there are lots of overlays.
 src/buffer.c (sort_overlays): Use SAFE_NALLOCA, to avoid segfault
 when there are lots of overlays.  See
 http://lists.gnu.org/archive/html/emacs-devel/2013-01/msg00421.html
 for the details and a way to reproduce.

1 files changed, 6 insertions, 1 deletions

diff --git a/src/buffer.c b/src/buffer.c
index 66581cb7828..aa3fcf8c234 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -3151,7 +3151,10 @@ ptrdiff_t
 sort_overlays (Lisp_Object *overlay_vec, ptrdiff_t noverlays, struct window *w)
 {
   ptrdiff_t i, j;
-  struct sortvec *sortvec = alloca (noverlays * sizeof *sortvec);
+  USE_SAFE_ALLOCA;
+  struct sortvec *sortvec;
+
+  SAFE_NALLOCA (sortvec, 1, noverlays);
 
   /* Put the valid and relevant overlays into sortvec.  */
 
@@ -3197,6 +3200,8 @@ sort_overlays (Lisp_Object *overlay_vec, ptrdiff_t noverlays, struct window *w)
 
   for (i = 0; i < noverlays; i++)
     overlay_vec[i] = sortvec[i].overlay;
+
+  SAFE_FREE ();
   return (noverlays);
 }