Fix long-standing excessive file merges
Since switching to the multihead approach, we've been creating
excessive file-level merges where files are marked as merged with
their ancestors.
This explicitly checks at commit time whether the two parent versions
are linearly related, and if so, reduces the file check-in to a
non-merge. Then the file is compared against the remaining parent,
and, if equal, skips check-in of that file (as it's not changed).
Since we're not checking in all files that were different between
versions, we no longer need to mark so many files for merge. This
removes most of the 'm' state marking as well.
Finally, it is possible to do a tree-level merge with no file-level
changes. This will happen if one user changes file A and another
changes file B. Thus, if we have have two parents, we allow commit to
proceed even if there are no file-level changes.
#!/bin/sh
cat <<'EOF' > merge
#!/bin/sh
echo merging for `basename $1`
EOF
chmod +x merge
HGMERGE=./merge; export HGMERGE
mkdir A1
cd A1
hg init
echo This is file foo1 > foo
echo This is file bar1 > bar
hg add foo bar
hg commit -m "commit text" -d "0 0"
cd ..
hg clone A1 B1
cd A1
rm bar
hg remove bar
hg commit -m "commit test" -d "0 0"
cd ../B1
echo This is file foo22 > foo
hg commit -m "commit test" -d "0 0"
cd ..
hg clone A1 A2
hg clone B1 B2
cd A1
hg pull ../B1
hg update -m
hg commit -m "commit test" -d "0 0"
echo bar should remain deleted.
hg manifest
cd ../B2
hg pull ../A2
hg update -m
hg commit -m "commit test" -d "0 0"
echo bar should remain deleted.
hg manifest