debugcolor: fix crash by empty styles (issue5856)

tests: explicitly define compression engines for tests The zstd compression engine requires C extensions and isn't present in pure Python builds. The compression engine list leaks into the server capabilities string. Unless we're testing functionality specific to a compression format, the set of compression formats supported by a server doesn't matter much. So this commit explicitly defines the server's compression engines for some tests so behavior is consistent between pure and non-pure builds. Differential Revision: https://phab.mercurial-scm.org/D3431

tests: update no-zstd branch of test-treediscovery.t as in 330ada7e8ea5 This side of the test got overlooked. We should probably consider having a way to run some of our tests through a "no-zstd" case just like we run some things through a "no-obsmarkers" case, but that's not an appropriate thing for stable. Differential Revision: https://phab.mercurial-scm.org/D3430

tests: glob away content-length changes relating to missing zstd bindings This doesn't fix everything in these two tests around missing zstd: we still get some changes in the CBOR payload in ways that I think we probably shouldn't bother to glob around. Maybe we should just disable zstd support in some of these lower-level wireproto tests? Differential Revision: https://phab.mercurial-scm.org/D3429

revlog: make pure version of _partialmatch() support 40-byte hex nodeids Without this patch, test-histedit-arguments.t would fail when run with --pure. It turned out to be because the pure version of _partialmatch() does not support full 40-byte hex nodeids. When histedit's instructions include things like "pick tip", it resolves the "tip" revision early to a full nodeid (but plain hex nodeid prefixes are not resolved to full nodeids). Then the nodeid (full or not) is looked up using to a full nodeid later. This step is what fails in pure mode. It has been failing since my c4131138eadb (histedit: look up partial nodeid as partial nodeid, 2018-04-06). I haven't verified, but I suspect histedit instructions like "pick <full hex nodeid>" would have been failing before my commit too, though. The fix is trivial: change a "< 40" to "<= 40". Differential Revision: https://phab.mercurial-scm.org/D3428

hgweb: reuse body file object when hgwebdir calls hgweb (issue5851) An unintended side-effect of f0a851542a05 was that the request body file object (which uses a util.cappedreader) was constructed twice when hgwebdir called into hgweb. Since we attempt to read all remaining data from this file object when Content-Length is defined and since there were two instances of this object and the client supplied no additional data to read, this resulted in deadlock. The fix implemented in this commit is to reuse the request body file object when it is passed from hgwebdir to hgweb. A test demonstrating `hg clone` and `hg push` via hgwebdir has been added. Without this patch, the test hangs when doing `hg clone`. Surprisingly, this must mean that we have effectively no test coverage of the wire protocol when run via hgwebdir. Differential Revision: https://phab.mercurial-scm.org/D3427