revlog: generate trivial deltas against null revision To avoid extra memory usage and performance issues with large files, generate a trivial delta header for deltas against the null revision rather than calling the usual delta generator. We append the delta header to meta rather than prepending it to data to avoid a large allocate and copy.

#!/bin/sh

echo "[extensions]" >> $HGRCPATH
echo "convert=" >> $HGRCPATH

hg init a
cd a
echo a > a
hg ci -d'0 0' -Ama
hg cp a b
hg ci -d'1 0' -mb
hg rm a
hg ci -d'2 0' -mc
hg mv b a
hg ci -d'3 0' -md
echo a >> a
hg ci -d'4 0' -me

cd ..
hg convert a 2>&1 | grep -v 'subversion python bindings could not be loaded'
hg --cwd a-hg pull ../a