mpatch: use int rather than ssize_t
We might need to be more clever than this to make Py2.5 happy.
#!/bin/sh
hg init repo
cd repo
touch foo
hg ci -Am 'add foo'
hg up -C null
# this should be stored as a delta against rev 0
echo foo bar baz > foo
hg ci -Am 'add foo again'
hg debugindex .hg/store/data/foo.i