convert/bzr: make it work with filemaps (
issue1631)
The bzr converter maintains a child -> parents mapping and drop entries
whenever a child is read. It does not work with filemaps, getchangedfiles() may
be called more than once when filtered files belong to merge revisions.
getchanges() still works that way but it is not clear whether a similar issue
can arise when interacting with merges.
hg init test
cd test
echo foo > a
hg ci -Ama
hg up -r0000
echo bar > a
echo % should issue warning
hg ci -Amb
hg up -r0000
echo stuffy > a
echo % should not issue warning
hg ci -q -Amc
hg up -r0000
echo crap > a
hg branch testing
echo % should not issue warning
hg ci -q -Amd