Avoid extra filelogs entries. Right now, there are some situations in which localrepo.filecommit can create filelog entries even though they're not needed. For example: - permissions for a file have changed; - qrefresh can create a filelog entry identical to its parent (see the added test); - convert-repo creates extra filelog entries in every merge where the first parent has added files (for example, changeset ebebe9577a1a of the kernel repo added extra filelog entries to files in the arch/blackfin directory, even though the merge should only touch the drivers/ata directory). This makes "hg log file" in a converted repo less useful than it could be, since it may mention many merges that don't actually touch that specific file. They all come from the same basic problem: localrepo.commit (through filecommit) creates new filelog entries for all files passed to it (except for some cases during a merge). Patch and test case provided by Benoit. This should fix issue351.

#!/bin/sh

cat >findbranch.py <<EOF
import re, sys

head_re = re.compile('^#(?:(?:\\s+([A-Za-z][A-Za-z0-9_]*)(?:\\s.*)?)|(?:\\s*))$')

for line in sys.stdin:
    hmatch = head_re.match(line)
    if not hmatch:
        sys.exit(1)
    if hmatch.group(1) == 'Branch':
        sys.exit(0)
sys.exit(1)
EOF
hg init a
cd a
echo "Rev 1" >rev
hg add rev
hg commit -m "No branch."
hg branch abranch
echo "Rev  2" >rev
hg commit -m "With branch."
if hg export 0 | python ../findbranch.py; then
    echo "Export of default branch revision has Branch header" 1>&2
    exit 1
fi
if hg export 1 | python ../findbranch.py; then
    :  # Do nothing
else
    echo "Export of branch revision is missing Branch header" 1>&2
    exit 1
fi
# Make sure import still works with branch information in patches.
cd ..
hg init b
cd b
hg -R ../a export 0 | hg import -
hg -R ../a export 1 | hg import -
cd ..
rm -rf b
hg init b
cd b
hg -R ../a export 0 | hg import --exact -
hg -R ../a export 1 | hg import --exact -