/* Work around a bug of lstat on some systems

   Copyright (C) 1997-2006, 2008-2017 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* written by Jim Meyering */

/* If the user's config.h happens to include <sys/stat.h>, let it include only

   the system's <sys/stat.h> here, so that orig_lstat doesn't recurse to

   rpl_lstat.  */

#define __need_system_sys_stat_h

#include <config.h>

#if !HAVE_LSTAT

/* On systems that lack symlinks, our replacement <sys/stat.h> already

   defined lstat as stat, so there is nothing further to do other than

   avoid an empty file.  */

typedef int dummy;

#else /* HAVE_LSTAT */

/* Get the original definition of lstat.  It might be defined as a macro.  */

# include <sys/types.h>

# include <sys/stat.h>

# undef __need_system_sys_stat_h

static int

orig_lstat (const char *filename, struct stat *buf)

{

  return lstat (filename, buf);

}

/* Specification.  */

/* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc

   eliminates this include because of the preliminary #include <sys/stat.h>

   above.  */

# include "sys/stat.h"

# include <string.h>

# include <errno.h>

/* lstat works differently on Linux and Solaris systems.  POSIX (see

   "pathname resolution" in the glossary) requires that programs like

   'ls' take into consideration the fact that FILE has a trailing slash

   when FILE is a symbolic link.  On Linux and Solaris 10 systems, the

   lstat function already has the desired semantics (in treating

   'lstat ("symlink/", sbuf)' just like 'lstat ("symlink/.", sbuf)',

   but on Solaris 9 and earlier it does not.

   If FILE has a trailing slash and specifies a symbolic link,

   then use stat() to get more info on the referent of FILE.

   If the referent is a non-directory, then set errno to ENOTDIR

   and return -1.  Otherwise, return stat's result.  */

int

rpl_lstat (const char *file, struct stat *sbuf)

{

  size_t len;

  int lstat_result = orig_lstat (file, sbuf);

  if (lstat_result != 0)

    return lstat_result;

  /* This replacement file can blindly check against '/' rather than

     using the ISSLASH macro, because all platforms with '\\' either

     lack symlinks (mingw) or have working lstat (cygwin) and thus do

     not compile this file.  0 len should have already been filtered

     out above, with a failure return of ENOENT.  */

  len = strlen (file);

  if (file[len - 1] != '/' || S_ISDIR (sbuf->st_mode))

    return 0;

  /* At this point, a trailing slash is only permitted on

     symlink-to-dir; but it should have found information on the

     directory, not the symlink.  Call stat() to get info about the

     link's referent.  Our replacement stat guarantees valid results,

     even if the symlink is not pointing to a directory.  */

  if (!S_ISLNK (sbuf->st_mode))

    {

      errno = ENOTDIR;

      return -1;

    }

  return stat (file, sbuf);

}

#endif /* HAVE_LSTAT */