# HG changeset patch
# User Jim Meyering <jim@meyering.net>
# Date 1159266606 0
# Node ID 9b51e5cb4829c0c11f5cd642d3e465a7b4e71d48
# Parent  b36917ecc3fdd29dfe5adc406c22a0b0bb8f3ae0
* acl.m4 (AC_FUNC_ACL): Disable ACL support altogether
when we detect Darwin 8.7.0's acl_get_file bug.
Rearrange to perform the new (below) run-test while $LIBS
contains any acl-related library.  Set USE_ACL at the end.
(gl_ACL_GET_FILE): New function.

diff --git a/m4/ChangeLog b/m4/ChangeLog
--- a/m4/ChangeLog
+++ b/m4/ChangeLog
@@ -1,3 +1,11 @@
+2006-09-26  Jim Meyering  <jim@meyering.net>
+
+	* acl.m4 (AC_FUNC_ACL): Disable ACL support altogether
+	when we detect Darwin 8.7.0's acl_get_file bug.
+	Rearrange to perform the new (below) run-test while $LIBS
+	contains any acl-related library.  Set USE_ACL at the end.
+	(gl_ACL_GET_FILE): New function.
+
 2006-09-25  Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
 
 	* host-os.m4 (gl_HOST_OS): Require AC_CANONICAL_HOST.
diff --git a/m4/acl.m4 b/m4/acl.m4
--- a/m4/acl.m4
+++ b/m4/acl.m4
@@ -5,7 +5,7 @@
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
 
-# Written by Paul Eggert.
+# Written by Paul Eggert and Jim Meyering.
 
 AC_DEFUN([AC_FUNC_ACL],
 [
@@ -13,22 +13,50 @@
 
   dnl Prerequisites of lib/acl.c.
   AC_CHECK_HEADERS(sys/acl.h)
-  if test "$ac_cv_header_sys_acl_h" = yes; then
-    use_acl=1
-  else
-    use_acl=0
-  fi
-  AC_DEFINE_UNQUOTED(USE_ACL, $use_acl,
-		     [Define if you want access control list support.])
   AC_CHECK_FUNCS(acl)
   ac_save_LIBS="$LIBS"
-  AC_SEARCH_LIBS(acl_get_file, acl,
-		 [test "$ac_cv_search_acl_get_file" = "none required" ||
-		  LIB_ACL=$ac_cv_search_acl_get_file])
-  AC_SUBST(LIB_ACL)
-  AC_CHECK_HEADERS(acl/libacl.h)
-  AC_CHECK_FUNCS(acl_get_file acl_get_fd acl_set_file acl_set_fd \
-		 acl_free acl_from_mode acl_from_text acl_to_text \
-		 acl_delete_def_file acl_entries acl_extended_file)
+    AC_SEARCH_LIBS(acl_get_file, acl,
+		   [test "$ac_cv_search_acl_get_file" = "none required" ||
+		    LIB_ACL=$ac_cv_search_acl_get_file])
+    AC_SUBST(LIB_ACL)
+    AC_CHECK_HEADERS(acl/libacl.h)
+    AC_CHECK_FUNCS(acl_get_file acl_get_fd acl_set_file acl_set_fd \
+		   acl_free acl_from_mode acl_from_text acl_to_text \
+		   acl_delete_def_file acl_entries acl_extended_file)
+    if test "$ac_cv_header_sys_acl_h" = yes; then
+      use_acl=1
+      if test "$ac_cv_func_acl_get_file" = yes; then
+	# If we detect the acl_get_file bug, disable ACL support altogether.
+	gl_ACL_GET_FILE( , [use_acl=0])
+      fi
+    else
+      use_acl=0
+    fi
   LIBS="$ac_save_LIBS"
+  AC_DEFINE_UNQUOTED(USE_ACL, $use_acl,
+		     [Define if you want access control list support.])
 ])
+
+# gl_ACL_GET_FILE(IF-WORKS, IF-NOT)
+# -------------------------------------
+# If `acl_get_file' works (does not have a particular bug),
+# run IF-WORKS, otherwise, IF-NOT.
+# This tests for a Darwin 8.7.0 bug, whereby acl_get_file returns NULL,
+# but sets errno = ENOENT for an existing file or directory.
+AC_DEFUN([gl_ACL_GET_FILE],
+[
+  AC_CACHE_CHECK([for working acl_get_file], gl_cv_func_working_acl_get_file,
+    [AC_RUN_IFELSE(
+       [AC_LANG_PROGRAM(
+	  [[#include <sys/types.h>
+	   #include <sys/acl.h>
+	   #include <errno.h>
+	  ]],
+	  [[return !! (!acl_get_file (".", ACL_TYPE_ACCESS)
+		       || errno == ENOENT);]])],
+       [gl_cv_func_working_acl_get_file=yes],
+       [gl_cv_func_working_acl_get_file=no],
+       [gl_cv_func_working_acl_get_file=cross-compiling])])
+
+  AS_IF([test $gl_cv_func_working_acl_get_file = yes], [$1], [$2])
+])