templatefilters: avoid infinite recursion bug in stringify
This doesn't ever happen on Python 2, but it's been a persistent pain
on Python 3. Adding this helped produce some of my upcoming Python 3
fixes.
Differential Revision: https://phab.mercurial-scm.org/D2553
--- a/mercurial/templatefilters.py Fri Mar 02 00:37:55 2018 -0500
+++ b/mercurial/templatefilters.py Fri Mar 02 09:08:11 2018 -0500
@@ -376,6 +376,12 @@
"""
thing = templatekw.unwraphybrid(thing)
if util.safehasattr(thing, '__iter__') and not isinstance(thing, bytes):
+ if isinstance(thing, str):
+ # This is only reachable on Python 3 (otherwise
+ # isinstance(thing, bytes) would have been true), and is
+ # here to prevent infinite recursion bugs on Python 3.
+ raise error.ProgrammingError(
+ 'stringify got unexpected unicode string: %r' % thing)
return "".join([stringify(t) for t in thing if t is not None])
if thing is None:
return ""