# HG changeset patch
# User Jim Meyering <jim@meyering.net>
# Date 947349049 0
# Node ID a5f09f038aaac5a1f539c3c44fb503f6217eff38
# Parent  00ec6425c28ffb58f0e498851444c7a7e695506e
(jm_FUNC_STRERROR_R): New file/macro.

diff --git a/m4/strerror_r.m4 b/m4/strerror_r.m4
new file mode 100644
--- /dev/null
+++ b/m4/strerror_r.m4
@@ -0,0 +1,39 @@
+#serial 1
+
+dnl From Jim Meyering.
+dnl Determine whether the strerror_r implementation is one of
+dnl the broken ones that returns `int' rather than `char*'.
+dnl Actually, this tests only whether it returns an array,
+dnl but that should be enough.
+dnl This is used by lib/error.c.
+
+AC_DEFUN(jm_FUNC_STRERROR_R,
+[
+  # Check strerror_r
+  AC_CHECK_FUNCS([strerror_r])
+  if test $ac_cv_func_strerror_r = yes; then
+    AC_CHECK_HEADERS(string.h)
+    AC_CACHE_CHECK([for working strerror_r],
+                   jm_cv_func_working_strerror_r,
+     [
+      AC_TRY_COMPILE(
+       [
+#       include <stdio.h>
+#       if HAVE_STRING_H
+#        include <string.h>
+#       endif
+       ],
+       [
+	 int buf; /* avoiding square brackets makes this easier */
+	 char x = *strerror_r (0, buf, sizeof buf);
+       ],
+       jm_cv_func_working_strerror_r=yes,
+       jm_cv_func_working_strerror_r=no
+      )
+      if test $jm_cv_func_working_strerror_r = yes; then
+	AC_DEFINE_UNQUOTED(HAVE_WORKING_STRERROR_R, 1,
+	  [Define to 1 if strerror_r returns a string.])
+      fi
+    ])
+  fi
+])