testing: switch to inserting deltas As the comment in the test specifies, this was relying on storage backend implementation details. We switch to inserting a raw delta, skipping the regular insert path to ensure we have the desired outcome. This required implementing support for handling deltas in the revlog testing code. Differential Revision: https://phab.mercurial-scm.org/D5116

testing: remove expectation of error on bad node insert addgroup() doesn't necessarily validate the hashes of each incoming revision. This is an optimization that allows delta group application to complete faster. The fact that revlog raises in this particular test is an implementation detail due to the way revlogs are testing multiple deltas. Differential Revision: https://phab.mercurial-scm.org/D5115

storageutil: convert fileid to bytes to avoid cast to %s test-storage.py manages to trigger this on Python 3. Differential Revision: https://phab.mercurial-scm.org/D5117

tests: use byte literals in test-storage.py This fixes a Python 3 breakage due to unknown key due to str/bytes type mismatch. # skip-blame just b'' literals Differential Revision: https://phab.mercurial-scm.org/D5114

py3: byte-stringify literals in test-keyword.t # skip-blame just some b'' prefixes

py3: flush std streams before/after running user code in heredoctest.py Otherwise, things written to stdout.buffer would be interleaved.

py3: rewrite StringIO fallback for Python 3

py3: reinvent print() function for contrib/hgclient.py

py3: work around unicode stdio streams in contrib/hgclient.py

py3: convert string literals to bytes in contrib/hgclient.py # skip-blame just many b'' prefixes