merge: do early copy to deal with issue636
Without copies/renames, merges source names are 1:1 with their
targets. Copies and renames introduce the possibility that there will
be two merges with the same input but different output. By doing the
copy to the destination name before the merge, the actual merge
becomes 1:1 again, and no source is the input to two different merges.
- add a preliminary scan to applyupdates to do copies
- for the merge action, pass the old name (for finding ancestors) and
the new name (for input to the merge) to filemerge
- eliminate the old post-merge copy
- lookup file contents from new name in filemerge
- pass new name to external merge helper
- report merge failure at new name
- add a test
#!/bin/sh
HGMERGE=true; export HGMERGE
hg init basic
cd basic
echo '# should complain'
hg backout
hg backout -r 0 0
echo '# basic operation'
echo a > a
hg commit -d '0 0' -A -m a
echo b >> a
hg commit -d '1 0' -m b
hg backout -d '2 0' tip
cat a
echo '# file that was removed is recreated'
cd ..
hg init remove
cd remove
echo content > a
hg commit -d '0 0' -A -m a
hg rm a
hg commit -d '1 0' -m b
hg backout -d '2 0' --merge tip
cat a
echo '# backout of backout is as if nothing happened'
hg backout -d '3 0' --merge tip
cat a 2>/dev/null || echo cat: a: No such file or directory
echo '# backout with merge'
cd ..
hg init merge
cd merge
echo line 1 > a
hg commit -d '0 0' -A -m a
echo line 2 >> a
hg commit -d '1 0' -m b
echo line 3 >> a
hg commit -d '2 0' -m c
hg backout --merge -d '3 0' 1
hg commit -d '4 0' -m d
cat a
echo '# backout should not back out subsequent changesets'
hg init onecs
cd onecs
echo 1 > a
hg commit -d '0 0' -A -m a
echo 2 >> a
hg commit -d '1 0' -m b
echo 1 > b
hg commit -d '2 0' -A -m c
hg backout -d '3 0' 1
hg locate b
cd ..
hg init m
cd m
echo a > a
hg commit -d '0 0' -A -m a
echo b > b
hg commit -d '1 0' -A -m b
echo c > c
hg commit -d '2 0' -A -m b
hg update 1
echo d > d
hg commit -d '3 0' -A -m c
hg merge 2
hg commit -d '4 0' -A -m d
echo '# backout of merge should fail'
hg backout 4
echo '# backout of merge with bad parent should fail'
hg backout --parent 0 4
echo '# backout of non-merge with parent should fail'
hg backout --parent 0 3
echo '# backout with valid parent should be ok'
hg backout -d '5 0' --parent 2 4
hg rollback
hg update -C
hg backout -d '6 0' --parent 3 4
exit 0