hgtagsfnodescache: handle nullid lookup
The null revision is empty, so it `.hgtags` content is `nullid` in regards with
the `hgtagsfnodescache`. Dealing with `nullid` will help with the next
changeset. Before this change, feeding `nullid` to `hgtagsfnodescache.getfnode` would
return a wrong result (fnode for tip).
--- a/mercurial/tags.py Fri Apr 26 17:39:07 2019 +0200
+++ b/mercurial/tags.py Mon Mar 11 01:09:38 2019 +0100
@@ -691,6 +691,9 @@
If an .hgtags does not exist at the specified revision, nullid is
returned.
"""
+ if node == nullid:
+ return nullid
+
ctx = self._repo[node]
rev = ctx.rev()