Index: subversion/libsvn_repos/delta.c
===================================================================
--- subversion/libsvn_repos/delta.c	(.../trunk)	(revision 7163)
+++ subversion/libsvn_repos/delta.c	(.../dir_delta)	(revision 7163)
@@ -653,7 +653,61 @@
   return SVN_NO_ERROR;
 }
 
+static svn_error_t *
+compare_files (svn_boolean_t *changed_p,
+               svn_fs_root_t *root1,
+               const char *path1,
+               svn_fs_root_t *root2,
+               const char *path2,
+               apr_pool_t *pool)
+{
+  svn_filesize_t size1, size2;
+  SVN_ERR (svn_fs_contents_changed (changed_p, root1, path1,
+                                    root2, path2, pool));
+  if (!*changed_p)
+    return SVN_NO_ERROR;
 
+  *changed_p = FALSE;
+  SVN_ERR (svn_fs_file_length (&size1, root1, path1, pool));
+  SVN_ERR (svn_fs_file_length (&size2, root2, path2, pool));
+
+  if (size1 != size2)
+    *changed_p = TRUE;
+  else
+    {
+      unsigned char md51[APR_MD5_DIGESTSIZE], md52[APR_MD5_DIGESTSIZE];
+      SVN_ERR (svn_fs_file_md5_checksum (md51, root1, path1, pool));
+      SVN_ERR (svn_fs_file_md5_checksum (md52, root2, path2, pool));
+      if (!svn_md5_digests_match (md51, md52))
+        *changed_p = TRUE;
+    }
+
+  if (!*changed_p) {
+      svn_stream_t *stream1, *stream2;
+      char buf1[SVN_STREAM_CHUNK_SIZE], buf2[SVN_STREAM_CHUNK_SIZE];
+      apr_size_t len1, len2;
+
+      SVN_ERR (svn_fs_file_contents (&stream1, root1, path1, pool));
+      SVN_ERR (svn_fs_file_contents (&stream2, root2, path2, pool));
+
+      do
+        {
+          len1 = len2 = SVN_STREAM_CHUNK_SIZE;
+          SVN_ERR (svn_stream_read (stream1, buf1, &len1));
+          SVN_ERR (svn_stream_read (stream2, buf2, &len2));
+
+          if (len1 != len2 || memcmp (buf1, buf2, len1))
+            {
+              *changed_p = TRUE;
+              break;
+            }
+	}
+      while (len1 > 0);
+    }
+
+  return SVN_NO_ERROR;
+}
+
 /* Make the appropriate edits on FILE_BATON to change its contents and
    properties from those in SOURCE_PATH to those in TARGET_PATH. */
 static svn_error_t *
@@ -679,10 +733,16 @@
   if (source_path)
     {
       /* Is this deltification worth our time? */
-      SVN_ERR (svn_fs_contents_changed (&changed, 
-                                        c->target_root, target_path,
-                                        c->source_root, source_path,
-                                        subpool));
+      if (c->ignore_ancestry)
+        SVN_ERR (compare_files (&changed, 
+                                c->target_root, target_path,
+                                c->source_root, source_path,
+                                subpool));
+      else
+        SVN_ERR (svn_fs_contents_changed (&changed, 
+                                          c->target_root, target_path,
+                                          c->source_root, source_path,
+                                          subpool));
     }
   else
     {