tests/test-diff-upgrade

patch: support diff data loss detection and upgrade

In worst case, generating diff in upgrade mode can be two times more expensive
than generating it in git mode directly: we may have to regenerate the whole
diff again whenever a git feature is detected. Also, the first diff attempt is
completely buffered instead of being streamed. That said, even without having
profiled it yet, I am convinced we can fast-path the upgrade mode if necessary
were it to be used in regular diff commands, and not only in mq where avoiding
data loss is worth the price.

#!/bin/sh

echo "[extensions]" >> $HGRCPATH
echo "autodiff=$TESTDIR/autodiff.py" >> $HGRCPATH
echo "[diff]" >> $HGRCPATH
echo "nodates=1" >> $HGRCPATH

hg init repo
cd repo
echo '% make a combination of new, changed and deleted file'
echo regular > regular
echo rmregular > rmregular
touch rmempty
echo exec > exec
chmod +x exec
echo rmexec > rmexec
chmod +x rmexec
echo setexec > setexec
echo unsetexec > unsetexec
chmod +x unsetexec
echo binary > binary
python -c "file('rmbinary', 'wb').write('\0')"
hg ci -Am addfiles
echo regular >> regular
echo newregular >> newregular
rm rmempty
touch newempty
rm rmregular
echo exec >> exec
echo newexec > newexec
chmod +x newexec
rm rmexec
chmod +x setexec
chmod -x unsetexec
python -c "file('binary', 'wb').write('\0\0')"
python -c "file('newbinary', 'wb').write('\0')"
rm rmbinary
hg addremove

echo '% git=no: regular diff for all files'
hg autodiff --git=no

echo '% git=no: git diff for single regular file'
hg autodiff --git=yes regular

echo '% git=auto: regular diff for regular files and removals'
hg autodiff --git=auto regular newregular rmregular rmbinary rmexec

for f in exec newexec setexec unsetexec binary newbinary newempty rmempty; do
    echo '% git=auto: git diff for' $f
    hg autodiff --git=auto $f
done

echo '% git=warn: regular diff with data loss warnings'
hg autodiff --git=warn

echo '% git=abort: fail on execute bit change'
hg autodiff --git=abort regular setexec

echo '% git=abort: succeed on regular file'
hg autodiff --git=abort regular

cd ..