diff -r 000000000000 -r 4f2f89ce4247 WebKitTools/Scripts/webkitpy/common/prettypatch.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebKitTools/Scripts/webkitpy/common/prettypatch.py	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,66 @@
+# Copyright (c) 2010 Google Inc. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import os
+import tempfile
+
+
+class PrettyPatch(object):
+    # FIXME: PrettyPatch should not require checkout_root.
+    def __init__(self, executive, checkout_root):
+        self._executive = executive
+        self._checkout_root = checkout_root
+
+    def pretty_diff_file(self, diff):
+        # Diffs can contain multiple text files of different encodings
+        # so we always deal with them as byte arrays, not unicode strings.
+        assert(isinstance(diff, str))
+        pretty_diff = self.pretty_diff(diff)
+        diff_file = tempfile.NamedTemporaryFile(suffix=".html")
+        diff_file.write(pretty_diff)
+        diff_file.flush()
+        return diff_file
+
+    def pretty_diff(self, diff):
+        # pretify.rb will hang forever if given no input.
+        # Avoid the hang by returning an empty string.
+        if not diff:
+            return ""
+
+        pretty_patch_path = os.path.join(self._checkout_root,
+                                         "BugsSite", "PrettyPatch")
+        prettify_path = os.path.join(pretty_patch_path, "prettify.rb")
+        args = [
+            "ruby",
+            "-I",
+            pretty_patch_path,
+            prettify_path,
+        ]
+        # PrettyPatch does not modify the encoding of the diff output
+        # so we can't expect it to be utf-8.
+        return self._executive.run_command(args, input=diff, decode_output=False)