posix: Allow glob to match dangling symlinks [BZ #866]

This patch makes glob match dangling symlinks.  Compared to other glob
implementation (*BSD, bash, musl, and other shells as well), GLIBC seems
the be the only one that does not match dangling symlinks.  As for
comment #5 in BZ #866, POSIX does not have any strict specification for
dangling symlinks match and it is reasonable that trying to glob everything
in a path should return all types of files (such as for a 'rm *').  Also,
comment #7 shows even more example where GLIBC current behavior is
unexepected.

I avoided adding another GNU specific flag to set this behavior and
instead make it the default.  Although this change the semanthic from
previous implementation, I think adding another compat symbol to be
really unecessary as from aforementioned reasons (current behavior not
defined in any standard, general idea of different implementation is
to list dangling symbols).

This also sync glob with gnulib commit fd1daf4 (glob: match dangling
symlinks).

Checked on x86_64-linux-gnu and on a build using build-many-glibcs.py
for all major architectures.

	[BZ #866]
	[BZ #1062]
	* posix/Makefile (tests): Remove bug-glob1 and tst-glob_symlinks.
	* posix/bug-glob1.c: Remove file.
	* posix/tst-glob_symlinks.c: New file.
	* posix/glob.c (__lstat64): New macro.
	(is_dir): New function.
	(glob, glob_in_dir): Match symlinks even if they are dangling.
	(link_stat, link_exists_p): Remove.  All uses removed.

1 files changed, 0 insertions, 88 deletions

diff --git a/posix/bug-glob1.c b/posix/bug-glob1.c
deleted file mode 100644
index 05c2da7584..0000000000
--- a/posix/bug-glob1.c
+++ /dev/null
@@ -1,88 +0,0 @@
-/* Test case for globbing dangling symlink.  By Ulrich Drepper.  */
-#include <errno.h>
-#include <error.h>
-#include <glob.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-
-static void prepare (int argc, char *argv[]);
-#define PREPARE prepare
-static int do_test (void);
-#define TEST_FUNCTION do_test ()
-
-#include "../test-skeleton.c"
-
-
-static char *fname;
-
-static void
-prepare (int argc, char *argv[])
-{
-  if (argc < 2)
-    error (EXIT_FAILURE, 0, "missing argument");
-
-  size_t len = strlen (argv[1]);
-  static const char ext[] = "globXXXXXX";
-  fname = malloc (len + sizeof (ext));
-  if (fname == NULL)
-    error (EXIT_FAILURE, errno, "cannot create temp file");
- again:
-  strcpy (stpcpy (fname, argv[1]), ext);
-  fname = mktemp (fname);
-  if (fname == NULL || *fname == '\0')
-    error (EXIT_FAILURE, errno, "cannot create temp file name");
-  if (symlink ("bug-glob1-does-not-exist", fname) != 0)
-    {
-      if (errno == EEXIST)
-	goto again;
-
-      error (EXIT_FAILURE, errno, "cannot create symlink");
-    }
-  add_temp_file (fname);
-}
-
-
-static int
-do_test (void)
-{
-  glob_t gl;
-  int retval = 0;
-  int e;
-
-  e = glob (fname, 0, NULL, &gl);
-  if (e == 0)
-    {
-      printf ("glob(\"%s\") succeeded\n", fname);
-      retval = 1;
-    }
-  globfree (&gl);
-
-  size_t fnamelen = strlen (fname);
-  char buf[fnamelen + 2];
-
-  strcpy (buf, fname);
-  buf[fnamelen - 1] = '?';
-  e = glob (buf, 0, NULL, &gl);
-  if (e == 0)
-    {
-      printf ("glob(\"%s\") succeeded\n", buf);
-      retval = 1;
-    }
-  globfree (&gl);
-
-  strcpy (buf, fname);
-  buf[fnamelen] = '*';
-  buf[fnamelen + 1] = '\0';
-  e = glob (buf, 0, NULL, &gl);
-  if (e == 0)
-    {
-      printf ("glob(\"%s\") succeeded\n", buf);
-      retval = 1;
-    }
-  globfree (&gl);
-
-  return retval;
-}