formatter: remove now-unnecessary check for file-ness `templater.templatepath()` now returns non-`None` only for files, so the caller doesn't have to check. Differential Revision: https://phab.mercurial-scm.org/D8805

templater: make templatepath() not return directory paths The previous patch added a test showing an unusal error message. This make it more like other error messages. Differential Revision: https://phab.mercurial-scm.org/D8804

tests: show unusual error message for `hg log --style coal` It turns out that we show the full path when the given style name matches a subdirectory of `mercurial/templates/`. Differential Revision: https://phab.mercurial-scm.org/D8803

config: remove now-unused `abs` argument from `include` callback Differential Revision: https://phab.mercurial-scm.org/D8796

config: re-calculate absolute %include path in `include` callback This removes the last user of the `abs` argument for the `include` callback. The next patch will remove the argument. Differential Revision: https://phab.mercurial-scm.org/D8795

subrepoutil: use relative path for looking up config `%include`s The code was already working with relative paths in practice, since it passed in a (repo-)relative path into its local `read()` function. So all that this patch actually does is to switch to rename variables so we use the same path by a different name. This gets us closer to removing the "absolute" path from the `include` callback. Differential Revision: https://phab.mercurial-scm.org/D8794