HomePhabricator

py3: don't risk passing a None value to error.ManifestLookupError()

Authored by martinvonz.

Description

py3: don't risk passing a None value to error.ManifestLookupError()

This makes the test case added in 20dd2a259b0f (test-grep: add tests
for --follow with/without --diff and/or paths, 2020-09-11) pass on
Python 3.

Differential Revision: https://phab.mercurial-scm.org/D9030