convert: Using --dest-type svn crashed, if the source repo used tags.
The convert extension requires puttags(self, tags) to return a sequence
for a multi-variable assignment. If puttags implicitly returns None,
the code will break when trying to un-pack None for assignment.
% reverting to rev 0
reverting foo
M foo
diff --git a/foo b/foo
old mode 100755
new mode 100644