changegroup: move revchunk() from narrow
The monkeypatched revchunk for ellipses serving is a
completely independent implementation. We model it as such
in the changegroup code. revchunk() is now a simple proxy
function.
Again, I wish we had better APIs here. Especially since this
narrow code is part of cg1packer and cg1packer can't be used
with narrow. Class inheritance is wonky. And I will definitely
be making changes to changegroup code for delta generation.
As part of the code move, `node.nullrev` was replaced by
`nullrev`. And a reference to `orig` was replaced to call
`self._revchunknormal` directly.
Differential Revision: https://phab.mercurial-scm.org/D4063
#require test-repo
$ cd $TESTDIR/../contrib/fuzz
#if clang-libfuzzer
$ make -s clean all
#endif
#if no-clang-libfuzzer clang-6.0
$ make -s clean all CC=clang-6.0 CXX=clang++-6.0
#endif
#if no-clang-libfuzzer no-clang-6.0
$ exit 80
#endif
Just run the fuzzers for five seconds each to verify it works at all.
$ ./bdiff -max_total_time 5
$ ./mpatch -max_total_time 5
$ ./xdiff -max_total_time 5