New behavior is generally superior and more correct, except possibly
with regards to missing files. hg up . is now effectively a no-op,
which is probably the desired behavior for people expecting to move to
tip, but may surprise people who were expecting deleted files to
reappear.
case 1: update to .
a-w -> a-w
classic: ancestor a
missing recreated right?
rmed recreated WRONG
added forgotten WRONG
changed preserved RIGHT
conflicted can't happen
backward merge: ancestor a (NO EFFECT)
missing missing wrong?
rm'ed rm'ed RIGHT
added preserved RIGHT
changed preserved RIGHT
conflicted can't happen
case 2: update to ancestor of .
a-b-w -> b-w
\
a
classic: ancestor a
missing recreated right?
rmed recreated wrong?
added forgotten wrong?
changed preserved RIGHT
conflicted preserved wrong?
backwards merge: ancestor b
missing missing or conflict right?
rm'ed missing or conflict right?
changed preserved RIGHT
conflicted merge RIGHT
added preserved right?
We might be able to do something smarter about this in dirstate.status
for files in normallookup state, but that would require some extra
care to keep backwards compatibility.
