Import upstream version 1.27

[debian/tar] / m4 / link.m4

diff --git a/m4/link.m4 b/m4/link.m4
index 479083cb84bf48e2daa07201050ca183fa9d2b44..7cc0ceb91c698bbf169f506c89ead995cff97ebb 100644 (file)
--- a/m4/link.m4
+++ b/m4/link.m4
@@ -1,5 +1,5 @@
-# link.m4 serial 5
-dnl Copyright (C) 2009-2011 Free Software Foundation, Inc.
+# link.m4 serial 8
+dnl Copyright (C) 2009-2013 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -7,12 +7,12 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_LINK],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
   AC_CHECK_FUNCS_ONCE([link])
   if test $ac_cv_func_link = no; then
     HAVE_LINK=0
-    AC_LIBOBJ([link])
   else
-    AC_CACHE_CHECK([whether link handles trailing slash correctly],
+    AC_CACHE_CHECK([whether link obeys POSIX],
       [gl_cv_func_link_works],
       [touch conftest.a
        # Assume that if we have lstat, we can also check symlinks.
@@ -29,15 +29,27 @@ AC_DEFUN([gl_FUNC_LINK],
 #if HAVE_LSTAT
              if (!link ("conftest.lnk/", "conftest.b"))
                result |= 2;
+             if (rename ("conftest.a", "conftest.b"))
+               result |= 4;
+             if (!link ("conftest.b", "conftest.lnk"))
+               result |= 8;
 #endif
              return result;
            ]])],
          [gl_cv_func_link_works=yes], [gl_cv_func_link_works=no],
-         [gl_cv_func_link_works="guessing no"])
+         [case "$host_os" in
+                    # Guess yes on glibc systems.
+            *-gnu*) gl_cv_func_link_works="guessing yes" ;;
+                    # If we don't know, assume the worst.
+            *)      gl_cv_func_link_works="guessing no" ;;
+          esac
+         ])
        rm -f conftest.a conftest.b conftest.lnk])
-    if test "$gl_cv_func_link_works" != yes; then
-      REPLACE_LINK=1
-      AC_LIBOBJ([link])
-    fi
+    case "$gl_cv_func_link_works" in
+      *yes) ;;
+      *)
+        REPLACE_LINK=1
+        ;;
+    esac
   fi
 ])