Merge from gnulib

This incorporates:
2015-06-06 acl-permissions: pacify -Wsuggest-attribute=const
2015-06-05 stdio: Don't redefine gets when using C++
2015-06-05 acl-permissions: port to AIX, C89 HP-UX
2015-06-02 file-has-acl: fix build on Mac OS X 10
2015-06-01 gnulib-tool: concatenate lib_SOURCES to a single line
2015-06-01 pthread_sigmask: discount system version if a simple macro
2015-05-31 readlinkat: avoid OS X 10.10 trailing slash bug
* doc/misc/texinfo.tex, lib/acl-internal.h, lib/get-permissions.c:
* lib/readlinkat.c, lib/set-permissions.c, lib/stdio.in.h:
* m4/acl.m4, m4/pthread_sigmask.m4, m4/readlinkat.m4: Copy from gnulib.
* lib/gnulib.mk: Regenerate.

1 files changed, 18 insertions, 0 deletions

diff --git a/lib/readlinkat.c b/lib/readlinkat.c
index f4826f92028..c91cf0e8200 100644
--- a/lib/readlinkat.c
+++ b/lib/readlinkat.c
@@ -18,7 +18,10 @@
 
 #include <config.h>
 
+#include <errno.h>
 #include <unistd.h>
+#include <string.h>
+#include <sys/stat.h>
 
 #if HAVE_READLINKAT
 
@@ -27,6 +30,21 @@
 ssize_t
 rpl_readlinkat (int fd, char const *file, char *buf, size_t len)
 {
+# if READLINK_TRAILING_SLASH_BUG
+  size_t file_len = strlen (file);
+  if (file_len && file[file_len - 1] == '/')
+    {
+      /* Even if FILE without the slash is a symlink to a directory,
+         both lstat() and stat() must resolve the trailing slash to
+         the directory rather than the symlink.  We can therefore
+         safely use stat() to distinguish between EINVAL and
+         ENOTDIR/ENOENT, avoiding extra overhead of rpl_lstat().  */
+      struct stat st;
+      if (stat (file, &st) == 0)
+        errno = EINVAL;
+      return -1;
+    }
+# endif /* READLINK_TRAILING_SLASH_BUG */
   return readlinkat (fd, file, buf, len);
 }