# HG changeset patch
# User Paul Eggert <eggert@cs.ucla.edu>
# Date 1356850591 28800
# Node ID e101c2620c25443e6400189578e6ce48b751ea30
# Parent  de636633c6cd0943de93fc09477892f343521655
regex: port to hosts where malloc (0) == NULL

Reported by Aharon Robbins in
<http://sourceware.org/ml/libc-alpha/2012-12/msg00456.html>.
* lib/regex_internal.c (re_node_set_alloc):
Don't assume that malloc (0) yields nonnull.
* lib/regex_internal.h (MALLOC_0_IS_NONNULL): New macro.
* m4/regex.m4 (gl_PREREQ_REGEX): Require gl_EEMALLOC.
* modules/regex (Files): Add m4/eealloc.m4.

diff -r de636633c6cd -r e101c2620c25 ChangeLog
--- a/ChangeLog	Sat Dec 29 22:52:17 2012 -0800
+++ b/ChangeLog	Sat Dec 29 22:56:31 2012 -0800
@@ -1,5 +1,14 @@
 2012-12-29  Paul Eggert  <eggert@cs.ucla.edu>
 
+	regex: port to hosts where malloc (0) == NULL
+	Reported by Aharon Robbins in
+	<http://sourceware.org/ml/libc-alpha/2012-12/msg00456.html>.
+	* lib/regex_internal.c (re_node_set_alloc):
+	Don't assume that malloc (0) yields nonnull.
+	* lib/regex_internal.h (MALLOC_0_IS_NONNULL): New macro.
+	* m4/regex.m4 (gl_PREREQ_REGEX): Require gl_EEMALLOC.
+	* modules/regex (Files): Add m4/eealloc.m4.
+
 	regex: port to C89
 	Reported by Aharon Robbins in
 	<http://sourceware.org/ml/libc-alpha/2012-12/msg00456.html>.
diff -r de636633c6cd -r e101c2620c25 lib/regex_internal.c
--- a/lib/regex_internal.c	Sat Dec 29 22:52:17 2012 -0800
+++ b/lib/regex_internal.c	Sat Dec 29 22:56:31 2012 -0800
@@ -974,7 +974,7 @@
   set->alloc = size;
   set->nelem = 0;
   set->elems = re_malloc (Idx, size);
-  if (BE (set->elems == NULL, 0))
+  if (BE (set->elems == NULL, 0) && (MALLOC_0_IS_NONNULL || size != 0))
     return REG_ESPACE;
   return REG_NOERROR;
 }
diff -r de636633c6cd -r e101c2620c25 lib/regex_internal.h
--- a/lib/regex_internal.h	Sat Dec 29 22:52:17 2012 -0800
+++ b/lib/regex_internal.h	Sat Dec 29 22:56:31 2012 -0800
@@ -464,6 +464,12 @@
 # endif
 #endif
 
+#ifdef _LIBC
+# define MALLOC_0_IS_NONNULL 1
+#elif !defined MALLOC_0_IS_NONNULL
+# define MALLOC_0_IS_NONNULL 0
+#endif
+
 #ifndef MAX
 # define MAX(a,b) ((a) < (b) ? (b) : (a))
 #endif
diff -r de636633c6cd -r e101c2620c25 m4/regex.m4
--- a/m4/regex.m4	Sat Dec 29 22:52:17 2012 -0800
+++ b/m4/regex.m4	Sat Dec 29 22:56:31 2012 -0800
@@ -220,6 +220,7 @@
   AC_REQUIRE([AC_C_INLINE])
   AC_REQUIRE([AC_C_RESTRICT])
   AC_REQUIRE([AC_TYPE_MBSTATE_T])
+  AC_REQUIRE([gl_EEMALLOC])
   AC_CHECK_HEADERS([libintl.h])
   AC_CHECK_FUNCS_ONCE([isblank iswctype wcscoll])
   AC_CHECK_DECLS([isblank], [], [], [[#include <ctype.h>]])
diff -r de636633c6cd -r e101c2620c25 modules/regex
--- a/modules/regex	Sat Dec 29 22:52:17 2012 -0800
+++ b/modules/regex	Sat Dec 29 22:56:31 2012 -0800
@@ -8,6 +8,7 @@
 lib/regex_internal.h
 lib/regexec.c
 lib/regcomp.c
+m4/eealloc.m4
 m4/regex.m4
 m4/mbstate_t.m4