Add git-patch-to-hg-export.py

This will allow @tarek and I to use this easily. I also modified the script so
that you can provide it the URL to pull from to simplify the process.

bin/git-patch-to-hg-export.py

@@ -0,0 +1,96 @@
+#!/usr/bin/env python
+"""\
+Git patch to HG changeset patch converter.
+
+USAGE: git-patch-to-hg-export.py < git.patch > hg.patch
+"""
+
+from email.utils import parsedate_tz, mktime_tz
+import re
+import os
+import sys
+
+
+def git_patch_to_hg(fin, fout):
+    fout.write('# HG changeset patch\n')
+
+    subject_re = re.compile(r'^(RE:)?\s*(\[[^]]*\])?\s*', re.I)
+
+    # headers
+    for line in fin:
+        if line.startswith('From: '):
+            fout.write('# User %s' % line[6:])
+        elif line.startswith('Date: '):
+            t = parsedate_tz(line[6:])
+            timestamp = mktime_tz(t)
+            timezone = -t[-1]
+            fout.write('# Date %d %d\n' % (timestamp, timezone))
+        elif line.startswith('Subject: '):
+            subject = subject_re.sub('', line[9:])
+            fout.write(subject + '\n')
+        elif line == '\n' or line == '\r\n':
+            break
+
+    # commit message
+    for line in fin:
+        if line == '---\n':
+            break
+        fout.write(line)
+
+    # skip over the diffstat
+    for line in fin:
+        if line.startswith('diff --git'):
+            fout.write('\n' + line)
+            break
+
+    # diff
+    # NOTE: there will still be an index line after each diff --git, but it
+    # will be ignored
+    for line in fin:
+        fout.write(line)
+
+    # NOTE: the --/version will still be at the end, but it will be ignored
+
+
+def open_file():
+    if len(sys.argv) > 1:
+        if re.match('https?://', sys.argv[1]):
+            import requests
+            import io
+            resp = requests.get(sys.argv[1])
+            return io.StringIO(resp.content) if resp.ok else io.StringIO('')
+        elif os.path.exists(sys.argv[1]):
+            return open(sys.argv[1])
+    return sys.stdin
+
+
+if __name__ == "__main__":
+    patch_fd = open_file()
+    git_patch_to_hg(patch_fd, sys.stdout)
+
+
+__author__ = "Mark Lodato <lodatom@gmail.com>"
+
+__license__ = """
+This is the MIT license: http://www.opensource.org/licenses/mit-license.php
+
+Copyright (c) 2009 Mark Lodato
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to
+deal in the Software without restriction, including without limitation the
+rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+IN THE SOFTWARE.
+"""