(copy_internal): When preserving symlinks (--no-dereference) and the

destination file is a symlink, use stat (not xstat) to see if it points
back to the source.  Reported by James <james@albion.glarp.com>.

diff --git a/src/copy.c b/src/copy.c
index 14e488d691f65589b17c2d58c360d6f2c46288ff..9dac6de96670dab56f81de1f724cab8b7ca1aefc 100644 (file)
--- a/src/copy.c
+++ b/src/copy.c
@@ -362,9 +362,26 @@ copy_internal (const char *src_path, const char *dst_path,
        }
       else
        {
-         /* The file exists already.  */
+         int same;
 
-         if (src_sb.st_ino == dst_sb.st_ino && src_sb.st_dev == dst_sb.st_dev)
+         /* The destination file exists already.  */
+
+         same = (src_sb.st_ino == dst_sb.st_ino
+                 && src_sb.st_dev == dst_sb.st_dev);
+
+         /* If we're preserving symlinks (--no-dereference) and the
+            destination file is a symlink, use stat (not xstat) to
+            see if it points back to the source.  */
+         if (!same && !x->dereference && S_ISLNK (dst_sb.st_mode))
+           {
+             struct stat dst2_sb;
+             if (stat (dst_path, &dst2_sb) == 0
+                 && (src_sb.st_ino == dst2_sb.st_ino &&
+                     src_sb.st_dev == dst2_sb.st_dev))
+               same = 1;
+           }
+
+         if (same)
            {
              if (x->hard_link)
                return 0;
@@ -630,14 +647,14 @@ copy_internal (const char *src_path, const char *dst_path,
        {
          /* Preserve the owner and group of the just-`copied'
             symbolic link, if possible.  */
-#ifdef HAVE_LCHOWN
+# ifdef HAVE_LCHOWN
          if (DO_CHOWN (lchown, dst_path, src_sb.st_uid, src_sb.st_gid))
            {
              error (0, errno, _("preserving ownership for %s"), dst_path);
              goto un_backup;
            }
-#else
-# ifdef ROOT_CHOWN_AFFECTS_SYMLINKS
+# else
+#  ifdef ROOT_CHOWN_AFFECTS_SYMLINKS
          if (x->myeuid == 0)
            {
              if (DO_CHOWN (chown, dst_path, src_sb.st_uid, src_sb.st_gid))
@@ -651,13 +668,13 @@ copy_internal (const char *src_path, const char *dst_path,
              /* FIXME: maybe give a diagnostic: you must be root
                 to preserve ownership and group of symlinks.  */
            }
-# else
+#  else
          /* Can't preserve ownership of symlinks.
             FIXME: maybe give a warning or even error for symlinks
             in directories with the sticky bit set -- there, not
             preserving owner/group is a potential security problem.  */
+#  endif
 # endif
-#endif
        }
 
       return 0;
@@ -726,8 +743,11 @@ un_backup:
 static int
 valid_options (const struct cp_options *co)
 {
+  assert (co != NULL);
+
   /* FIXME: make sure xstat and dereference are consistent.  */
   assert (co->xstat);
+
   assert (co->sparse_mode != SPARSE_UNUSED);
 }