revlog: reduce memory usage in addgroup - use a buffer to extract the delta from a chunk - avoid concatenating to a compressed delta - use a buffer to directly extra full text from a trivial delta - delete chunk and delta objects after use

#!/bin/sh

hg init

echo % should fail
hg add .hg/00changelog.i

mkdir a
echo a > a/a
hg ci -Ama
ln -s a b
echo b > a/b

echo % should fail
hg add b/b

echo % should succeed
hg add b

echo % should still fail - maybe
hg add b/b

exit 0