install-reloc: Support multi-binary installation.

[gnulib.git] / lib / lchown.c

diff --git a/lib/lchown.c b/lib/lchown.c
index 9c420bb..ff48c18 100644 (file)
--- a/lib/lchown.c
+++ b/lib/lchown.c
@@ -1,10 +1,12 @@
 /* Provide a stub lchown function for systems that lack it.
-   Copyright (C) 1998, 1999 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   Copyright (C) 1998-1999, 2002, 2004, 2006-2007, 2009-2013 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
@@ -12,38 +14,104 @@
    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 */
 
 #include <config.h>
 
-#include <sys/types.h>
-#include <sys/stat.h>
+#include <unistd.h>
+
 #include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
-#include "lchown.h"
+#include <stdbool.h>
+#include <string.h>
+#include <sys/stat.h>
 
-/* Declare chown to avoid a warning.  Don't include unistd.h,
-   because it may have a conflicting prototype for lchown.  */
-int chown ();
+#if !HAVE_LCHOWN
+
+/* If the system chown does not follow symlinks, we don't want it
+   replaced by gnulib's chown, which does follow symlinks.  */
+# if CHOWN_MODIFIES_SYMLINK
+#  undef chown
+# endif
 
 /* Work just like chown, except when FILE is a symbolic link.
-   In that case, set errno to ENOSYS and return -1.  */
+   In that case, set errno to EOPNOTSUPP and return -1.
+   But if autoconf tests determined that chown modifies
+   symlinks, then just call chown.  */
 
 int
 lchown (const char *file, uid_t uid, gid_t gid)
 {
+# if HAVE_CHOWN
+#  if ! CHOWN_MODIFIES_SYMLINK
   struct stat stats;
 
   if (lstat (file, &stats) == 0 && S_ISLNK (stats.st_mode))
     {
-      errno = ENOSYS;
+      errno = EOPNOTSUPP;
       return -1;
     }
+#  endif
 
   return chown (file, uid, gid);
+
+# else /* !HAVE_CHOWN */
+  errno = ENOSYS;
+  return -1;
+# endif
 }
+
+#else /* HAVE_LCHOWN */
+
+# undef lchown
+
+/* Work around trailing slash bugs in lchown.  */
+int
+rpl_lchown (const char *file, uid_t uid, gid_t gid)
+{
+  bool stat_valid = false;
+  int result;
+
+# if CHOWN_CHANGE_TIME_BUG
+  struct stat st;
+
+  if (gid != (gid_t) -1 || uid != (uid_t) -1)
+    {
+      if (lstat (file, &st))
+        return -1;
+      stat_valid = true;
+      if (!S_ISLNK (st.st_mode))
+        return chown (file, uid, gid);
+    }
+# endif
+
+# if CHOWN_TRAILING_SLASH_BUG
+  if (!stat_valid)
+    {
+      size_t len = strlen (file);
+      if (len && file[len - 1] == '/')
+        return chown (file, uid, gid);
+    }
+# endif
+
+  result = lchown (file, uid, gid);
+
+# if CHOWN_CHANGE_TIME_BUG && HAVE_LCHMOD
+  if (result == 0 && stat_valid
+      && (uid == st.st_uid || uid == (uid_t) -1)
+      && (gid == st.st_gid || gid == (gid_t) -1))
+    {
+      /* No change in ownership, but at least one argument was not -1,
+         so we are required to update ctime.  Since lchown succeeded,
+         we assume that lchmod will do likewise.  But if the system
+         lacks lchmod and lutimes, we are out of luck.  Oh well.  */
+      result = lchmod (file, st.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO
+                                           | S_ISUID | S_ISGID | S_ISVTX));
+    }
+# endif
+
+  return result;
+}
+
+#endif /* HAVE_LCHOWN */