template: add predecessors template Add a 'predecessors' template that returns the list of all closest known predecessors for a changectx. The elements of the list are row changectx node id formatted by default as short nodes. The "closest predecessors" are the first locally known revisions encountered while, walking predecessors markers. For example: 1) If a (A, (B)) markers exists and both A and B are locally known A is a closest predecessors of B. 2) If a (A, (B)) and (B, (C)) markers exists and only A and C are known locally, A will be the closest precursors of C. This logic respect repository filtering. So hidden revision will be skipped by this logic unless --hidden is specified. Since we only display the visible predecessors, this template will not display anything in most case. It makes a good candidate for inclusion in the default log output. I added a new test-file for testing the precursors in various scenarios. This test file will also be used for the successors template. A new "obsutil" module has been added to start gathering utility function outside of the large obsolete.py module.

commit: select template by spec.ref name And load all templates defined in [committemplate] since the selected template is no longer be named as 'changeset'.

commit: do not look up committemplate in template paths (BC) From 5375ba75df40 and de5cee8ba088, I don't think the current behavior is intended. Commit templates should be processed as literal templates.

formatter: always store a literal template unnamed Now spec.ref should be '' if spec.tmpl is specified. Since spec.ref is the option to select the initial template to be rendered, it doesn't make sense to store the given literal template as spec.ref.

formatter: load templates section like a map file Since a map file has another level to select a template (spec -> mapfile -> topic), this isn't exactly the same as how a map file works. But I believe most users would expect the new behavior. A literal template is stored as an unnamed template so that it will never conflict with the templates defined in [templates] section.

test-command-template: rewrite recursion tests by using a map file A literal template will be unnamed soon, so no recursion will be practically made by using -T option.

templater: add simple interface for unnamed template (API) This provides a simpler API for callers which don't need full templating stack. Instead of storing the given template as the name specified by topic, use '' as the default template to be rendered.

ui: add support for a tweakdefaults knob We've been talking for years about a one-stop config knob to opt in to better behavior. There have been a lot of ideas thrown around, but they all seem to be too complicated to get anyone to actually do the work.. As such, this patch is the stupidest thing that can possibly work in the name of getting a good feature to users. Right now it's just three config settings that I think are generally uncontroversial, but I expect to add more soon. That will likely include adding new config knobs for the express purpose of adding them to tweakdefaults.

localrepo: remove unused addchangegroup() (API) This completes the cleanup started in d3775db748a0 (localrepo: move the addchangegroup method in changegroup module, 2014-04-01).

changegroup: rename "dh" to the clearer "deltaheads" We have a lot of frequently used abbreviations, but this is not one of them.