changegroup: avoid large copies - handle chunk headers separately rather than prepending them to (potentially large) chunks - break large chunks into 1M pieces for compression - don't prepend file metadata onto (potentially large) file data

#!/bin/sh

hg init
echo a > a
hg ci -Am t

hg mv a b
hg ci -Am t1
hg debugrename b

hg mv b a
hg ci -Am t2
hg debugrename a

echo % test with --rev
hg debugrename --rev 1 b