X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Frealloc.m4;h=7695e89c852fb1cc57064d2e3caf85bbdcf8e971;hb=d374f61ddcf9d79d92bf407b5e6ba0e4847b1a90;hp=b4afe939d0e6fc04d3f35b7694bd6314a5650c84;hpb=47a93f77a5ec7f3515a06e91218626f01312c702;p=gnulib.git

diff --git a/m4/realloc.m4 b/m4/realloc.m4
index b4afe939d..7695e89c8 100644
--- a/m4/realloc.m4
+++ b/m4/realloc.m4
@@ -1,33 +1,35 @@
-#serial 1
+#serial 6
 
 dnl From Jim Meyering.
-dnl Determine whether realloc accepts 0 as its first argument.
+dnl Determine whether realloc works when both arguments are 0.
 dnl If it doesn't, arrange to use the replacement function.
 dnl
-dnl If you use this macro in a package, you should
-dnl add the following two lines to acconfig.h:
-dnl  /* Define to rpl_realloc if the replacement function should be used.  */
-dnl  #undef realloc
-dnl
 
-AC_DEFUN(jm_FUNC_REALLOC,
+AC_DEFUN([jm_FUNC_REALLOC],
 [
- AC_CACHE_CHECK([for working realloc], jm_cv_func_working_realloc,
+ dnl xmalloc.c requires that this symbol be defined so it doesn't
+ dnl mistakenly use a broken realloc -- as it might if this test were omitted.
+ AC_DEFINE(HAVE_DONE_WORKING_REALLOC_CHECK, 1,
+           [Define if the realloc check has been performed. ])
+
+ AC_CACHE_CHECK([whether realloc(0,0) returns a non-NULL pointer],
+                jm_cv_func_working_realloc,
   [AC_TRY_RUN([
     char *realloc ();
     int
     main ()
     {
-      exit (realloc (0, 1) ? 0 : 1);
+      exit (realloc (0, 0) ? 0 : 1);
     }
 	  ],
 	 jm_cv_func_working_realloc=yes,
 	 jm_cv_func_working_realloc=no,
-	 dnl When crosscompiling, assume realloc is broken.
+	 dnl When crosscompiling, assume realloc(0,0) returns NULL.
 	 jm_cv_func_working_realloc=no)
   ])
   if test $jm_cv_func_working_realloc = no; then
-    LIBOBJS="$LIBOBJS realloc.o"
-    AC_DEFINE_UNQUOTED(realloc, rpl_realloc)
+    AC_LIBOBJ(realloc)
+    AC_DEFINE(realloc, rpl_realloc,
+      [Define to rpl_realloc if the replacement function should be used.])
   fi
 ])