convert: replace old sha1s in the description

This is a simple find-and-replace strategy for matching anything in the
old description of a converted commit and, if that matched sha1 exists
in the mapping, replacing it with the new sha1.

In particular, this is helpful for descriptions that contain tags with
messages such as, "Added tag 1.0 for commit abcde1234567" which will now
be automatically converted.

Tests have been updated accordingly.

hgext/convert/hg.py

@@ -25,6 +25,9 b' from mercurial import hg, util, context,'
 
 from common import NoRepo, commit, converter_source, converter_sink
 
+import re
+sha1re = re.compile(r'\b[0-9a-f]{6,40}\b')
+
 class mercurial_sink(converter_sink):
     def __init__(self, ui, path):
         converter_sink.__init__(self, ui, path)
@@ -157,6 +160,14 b' class mercurial_sink(converter_sink):'
         p2 = parents.pop(0)
 
         text = commit.desc
+
+        sha1s = re.findall(sha1re, text)
+        for sha1 in sha1s:
+            oldrev = source.lookuprev(sha1)
+            newrev = revmap.get(oldrev)
+            if newrev is not None:
+                text = text.replace(sha1, newrev[:len(sha1)])
+
         extra = commit.extra.copy()
         if self.branchnames and commit.branch:
             extra['branch'] = commit.branch

tests/test-convert-hg-sink.t

@@ -119,7 +119,7 b' test tag rewriting'
   0 add baz
   $ cd new-filemap
   $ hg tags
-  tip                                2:6f4fd1df87fb
+  tip                                2:3c74706b1ff8
   some-tag                           0:ba8636729451
   $ cd ..