do not treat a failed rcscheckout() as system failure
A failed checkout is not necessarily caused by a solid system error, but
can be also caused by a faulty RCS file. Do not use rb_sys_fail(), since
it will abort() if errno == 0. Instead, simply raise a RuntimeError.
Reported-by: Brad King
check deltas for correctness before applying
We can not blindly trust the RCS file to contain correct deltas. We have
to verify that the chunks (especially deletes) make sense and operate on
existing lines.
Reported-by: Brad King
38:
Add test target to check out all rcs revs.
39:
Keep all delta stringinfos cached while running down the
file when creating a checkout.
40:
Cache delta handling as well.
41:
Use rcsparsetext also to obtain the log. Fix bug when
running down the revs.
