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 -e

umask 027
mkdir test1
cd test1

hg init
touch a b
hg add a b
hg ci -m "added a b" -d "1000000 0"

cd ..
hg clone test1 test3
mkdir test2
cd test2

hg init
hg pull ../test1
hg co
chmod +x a
hg ci -m "chmod +x a" -d "1000000 0"
echo % the changelog should mention file a:
hg tip --template '#files#\n'

cd ../test1
echo 123 >>a
hg ci -m "a updated" -d "1000000 0"

hg pull ../test2
hg heads
hg history

hg -v merge

cd ../test3
echo 123 >>b
hg ci -m "b updated" -d "1000000 0"

hg pull ../test2
hg heads
hg history

hg -v merge

ls -l ../test[123]/a > foo
cut -b 1-10 < foo

hg debugindex .hg/store/data/a.i
hg debugindex ../test2/.hg/store/data/a.i
hg debugindex ../test1/.hg/store/data/a.i