convert: add a mode where mercurial_sink skips empty revisions.
The getchanges function of some converter_source classes can return
some false positives. I.e. they sometimes claim that a file "foo"
was changed in some revision, even though its contents are still the
same.
convert_svn is particularly bad, but I think this can also happen with
convert_cvs and, at least in theory, with mercurial_source.
For regular conversions this is not really a problem - as long as
getfile returns the right contents, we'll get a converted revision
with the right contents. But when we use --filemap, this could lead
to superfluous revisions being converted.
Instead of fixing every converter_source, I decided to change
mercurial_sink to work around this problem.
When --filemap is used, we're interested only in revisions that touch
some specific files. If a revision doesn't change any of these files,
then we're not interested in it (at least for revisions with a single
parent; merges are special).
For mercurial_sink, we abuse this property and rollback a commit if
the manifest text hasn't changed. This avoids duplicating the logic
from localrepo.filecommit to detect unchanged files.
#!/bin/sh
# This test makes sure that we don't mark a file as merged with its ancestor
# when we do a merge.
cat <<EOF > merge
import sys, os
print "merging for", os.path.basename(sys.argv[1])
EOF
HGMERGE="python ../merge"; export HGMERGE
echo creating base
hg init a
cd a
echo 1 > foo
echo 1 > bar
echo 1 > baz
echo 1 > quux
hg add foo bar baz quux
hg commit -m "base" -d "1000000 0"
cd ..
hg clone a b
echo creating branch a
cd a
echo 2a > foo
echo 2a > bar
hg commit -m "branch a" -d "1000000 0"
echo creating branch b
cd ..
cd b
echo 2b > foo
echo 2b > baz
hg commit -m "branch b" -d "1000000 0"
echo "we shouldn't have anything but n state here"
hg debugstate | cut -b 1-16,35-
echo merging
hg pull ../a
hg merge -v
echo 2m > foo
echo 2b > baz
echo new > quux
echo "we shouldn't have anything but foo in merge state here"
hg debugstate | cut -b 1-16,35- | grep "^m"
hg ci -m "merge" -d "1000000 0"
echo "main: we should have a merge here"
hg debugindex .hg/store/00changelog.i
echo "log should show foo and quux changed"
hg log -v -r tip
echo "foo: we should have a merge here"
hg debugindex .hg/store/data/foo.i
echo "bar: we shouldn't have a merge here"
hg debugindex .hg/store/data/bar.i
echo "baz: we shouldn't have a merge here"
hg debugindex .hg/store/data/baz.i
echo "quux: we shouldn't have a merge here"
hg debugindex .hg/store/data/quux.i
echo "manifest entries should match tips of all files"
hg manifest --debug
echo "everything should be clean now"
hg status
hg verify