mercurial/match.py

--- a/mercurial/match.py	Wed Apr 10 03:10:53 2019 +0530
+++ b/mercurial/match.py	Thu Apr 11 18:34:56 2019 +0200
@@ -1288,7 +1288,7 @@
 
         if startidx == 0:
             matcher = _rematcher(fullregexp)
-            func = lambda s: matcher(s) is not None
+            func = lambda s: bool(matcher(s))
         else:
             group = regexps[startidx:]
             allgroups.append(_joinregexes(group))