openat: test for fstatat (..., 0) bug

[gnulib.git] / m4 / getcwd.m4

diff --git a/m4/getcwd.m4 b/m4/getcwd.m4
index 269fdd7..d3bbe59 100644 (file)
--- a/m4/getcwd.m4
+++ b/m4/getcwd.m4
@@ -6,7 +6,7 @@
 # with or without modifications, as long as this notice is preserved.
 
 # Written by Paul Eggert.
-# serial 7
+# serial 8
 
 AC_DEFUN([gl_FUNC_GETCWD_NULL],
   [
@@ -37,9 +37,6 @@ AC_DEFUN([gl_FUNC_GETCWD_NULL],
                return 0;
              }
 #endif
-         /* If size is non-zero, allocation must fail if size is too small */
-         if (getcwd (NULL, 1))
-           return 5;
          ]])],
         [gl_cv_func_getcwd_null=yes],
         [gl_cv_func_getcwd_null=no],
@@ -55,6 +52,24 @@ AC_DEFUN([gl_FUNC_GETCWD_NULL],
         ]])])
 ])
 
+AC_DEFUN([gl_FUNC_GETCWD_SIGNATURE],
+[
+  AC_CACHE_CHECK([for getcwd with POSIX signature],
+    [gl_cv_func_getcwd_posix_signature],
+    [AC_COMPILE_IFELSE(
+      [AC_LANG_PROGRAM(
+         [[#include <unistd.h>]],
+         [[extern
+           #ifdef __cplusplus
+           "C"
+           #endif
+           char *getcwd (char *, size_t);
+         ]])
+      ],
+      [gl_cv_func_getcwd_posix_signature=yes],
+      [gl_cv_func_getcwd_posix_signature=no])
+   ])
+])
 
 dnl Guarantee that getcwd will malloc with a NULL first argument.  Assumes
 dnl that either the system getcwd is robust, or that calling code is okay
@@ -67,9 +82,10 @@ AC_DEFUN([gl_FUNC_GETCWD_LGPL],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_GETCWD_NULL])
+  AC_REQUIRE([gl_FUNC_GETCWD_SIGNATURE])
 
-  case $gl_cv_func_getcwd_null in
-  *yes) ;;
+  case $gl_cv_func_getcwd_null,$gl_cv_func_getcwd_posix_signature in
+  *yes,yes) ;;
   *)
     dnl Minimal replacement lib/getcwd-lgpl.c.
     REPLACE_GETCWD=1
@@ -83,6 +99,7 @@ AC_DEFUN([gl_FUNC_GETCWD],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_GETCWD_NULL])
+  AC_REQUIRE([gl_FUNC_GETCWD_SIGNATURE])
   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
 
   gl_abort_bug=no
@@ -94,8 +111,8 @@ AC_DEFUN([gl_FUNC_GETCWD],
     gl_FUNC_GETCWD_ABORT_BUG([gl_abort_bug=yes]);;
   esac
 
-  case $gl_cv_func_getcwd_null,$gl_cv_func_getcwd_path_max,$gl_abort_bug in
-  *yes,yes,no) ;;
+  case $gl_cv_func_getcwd_null,$gl_cv_func_getcwd_posix_signature$gl_cv_func_getcwd_path_max,$gl_abort_bug in
+  *yes,yes,yes,no) ;;
   *)
     dnl Full replacement lib/getcwd.c, overrides LGPL replacement.
     REPLACE_GETCWD=1;;