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 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