X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Flstat.c;h=db119a10d3f48db6f760dab5953696eb6b49902b;hb=0e1c6ff93f27c939ba9e0df945b16ef98eaaeef1;hp=6dca99cbc5c7f228352eb7511ee3378eeb798ec7;hpb=a93d455afcb05ce04ac4e9e8fda046d6b4ef4814;p=gnulib.git

diff --git a/lib/lstat.c b/lib/lstat.c
index 6dca99cbc..db119a10d 100644
--- a/lib/lstat.c
+++ b/lib/lstat.c
@@ -1,12 +1,11 @@
-/* Work around the bug in some systems whereby lstat succeeds when
-   given the zero-length file name argument.  The lstat from SunOS4.1.4
-   has this bug.
-   Copyright (C) 1997, 1998 Free Software Foundation, Inc.
+/* Work around a bug of lstat on some systems
 
-   This program is free software; you can redistribute it and/or modify
+   Copyright (C) 1997-2006, 2008-2012 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 2, or (at your option)
-   any later version.
+   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
@@ -14,36 +13,85 @@
    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, write to the Free Software Foundation,
-   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   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>
 
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
+#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 inline 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"
 
-/* This is a wrapper for lstat(2).
-   If FILE is the empty string, fail with errno == ENOENT.
-   Otherwise, return the result of calling the real lstat.
+# include <string.h>
+# include <errno.h>
 
-   This works around the bug in some systems whereby lstat succeeds when
-   given the zero-length file name argument.  The lstat from SunOS4.1.4
-   has this bug.  */
+/* 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)
 {
-  if (file && *file == 0)
+  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 = ENOENT;
+      errno = ENOTDIR;
       return -1;
     }
-
-  return lstat (file, sbuf);
+  return stat (file, sbuf);
 }
+
+#endif /* HAVE_LSTAT */