Fix lifetime error in previous patch

Problem reported by Pip Cet in:
https://lists.gnu.org/r/emacs-devel/2019-07/msg00520.html
* src/alloc.c (inhibit_garbage_collection): Use new function.
(allow_garbage_collection): Accept intmax_t, not pointer.
* src/eval.c (default_toplevel_binding, do_one_unbind)
(backtrace_eval_unrewind, Fbacktrace__locals, mark_specpdl):
Support SPECPDL_UNWIND_INTMAX.
(record_unwind_protect_excursion): New function.
* src/lisp.h (enum specbind_tag): New constant SPECPDL_UNWIND_INTMAX.
(union specbinding): New member unwind_intmax.

1 files changed, 3 insertions, 5 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 50015808e59..aa9200f2ebb 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -5505,10 +5505,9 @@ staticpro (Lisp_Object const *varaddress)
    consing_until_gc to speed up maybe_gc when GC is inhibited.  */
 
 static void
-allow_garbage_collection (void *ptr)
+allow_garbage_collection (intmax_t consing)
 {
-  object_ct *p = ptr;
-  consing_until_gc = *p;
+  consing_until_gc = consing;
   garbage_collection_inhibited--;
 }
 
@@ -5516,8 +5515,7 @@ ptrdiff_t
 inhibit_garbage_collection (void)
 {
   ptrdiff_t count = SPECPDL_INDEX ();
-  object_ct consing = consing_until_gc;
-  record_unwind_protect_ptr (allow_garbage_collection, &consing);
+  record_unwind_protect_intmax (allow_garbage_collection, consing_until_gc);
   garbage_collection_inhibited++;
   consing_until_gc = OBJECT_CT_MAX;
   return count;