scmutil: make shortesthexnodeidprefix() take a full binary nodeid The shortest() template function depended on the behavior of revlog._partialmatch() for these types of inputs: * non-hex strings * ambiguous strings * too long strings revlog._partialmatch() seems to return the input unchanged in these cases, but we shouldn't depend on such a low-level function to match the behavior we want in the user-facing template function. Instead, let's handle these cases in the template function and always pass a binary nodeid to _partialmatch(). Differential Revision: https://phab.mercurial-scm.org/D3371

scmutil: make shortesthexnodeidprefix() use unfiltered repo Both callers were doing this, and resolvehexnodeidprefix() was also working on the unfiltered repo, so it makes more sense to have it all in one place. Differential Revision: https://phab.mercurial-scm.org/D3313

templates: adjust white space amount in the output of {whyunstable} There used to be 2 spaces between divergent nodes (when not using custom template for divergentnodes) because divergentnodes is a hybrid list, which means it gets ' '.join()ed, but formatnode() already had a space. Now it doesn't, which requires extra effort in writing custom templates for whyunstable, but at least it looks correctly by default. Test output needs to be sorted for stability.

tests: split long templates that use {whyunstable} and put them in hgrc

tests: make custom templates that use {whyunstable} terser These templates demonstrate that {whyunstable} is fully template-friendly, but they don't need to produce such long lines of output.

tests: hg log shouldn't need --hidden to show whyunstable template keyword

makefile: add Ubuntu Bionic docker targets (.deb and ppa) Bionic Beaver is an LTS release, supported until 2023-04.