revset: port extra() to support keyword arguments This is an example to show how keyword arguments are processed.

revset: add function to build dict of positional and keyword arguments Keyword arguments will be convenient for functions that will take more than one optional or boolean flags. For example, file(pattern[, subrepos=false]) subrepo([[pattern], status]) Because I don't think all functions should accept key=value syntax, getkwargs() does not support variadic functions such as 'ancestor(*changeset)'. The core logic is placed in the parser module because keyword arguments will be more useful in the templater, where functions take more options. Test cases will be added by the next patch.

revset: add parsing rule for key=value pair It will be used as an keyword argument. Note that our "=" operator is left-associative. In general, the assignment operator is right-associative, but we don't care because it isn't allowed to chain "=" operations.

import-checker: establish modern import convention We introduce a new convention for declaring imports and enforce it via the import checker script. The new convention is only active when absolute imports are used, which is currently nowhere. Keying off "from __future__ import absolute_import" to engage the new import convention seems like the easiest solution. It is also beneficial for Mercurial to use this mode because it means less work and ambiguity for the importer and potentially better performance due to fewer stat() system calls because the importer won't look for modules in relative paths unless explicitly asked. Once all files are converted to use absolute import, we can refactor this code to again only have a single import convention and we can require use of absolute import in the style checker. The rules for the new convention are documented in the docstring of the added function. Tests have been added to test-module-imports.t. Some tests are sensitive to newlines and source column position, which makes docstring testing difficult and/or impossible.

import-checker: establish new function for verifying import conventions A future patch will formalize the modern import convention. In preparation for that, introduce a new wrapper function that will invoke the proper function.

import-checker: resolve relative imports "from . import X" will produce an ImportFrom ast node with .module = None. This resulted in a run-time error from attempting to concatenate None with a str. Another problem with relative imports is that the prefix may be dynamic based on the "level" attribute of the import. e.g. "from ." has level 1 and "from .." has level 2. We teach the "fromlocal" function how to cope with relative imports. Where appropriate, the consumer passes in the level so relative module names may be resolved properly.

templatekw: use a list of tags in getlatesttags() instead of joining them This will be used in the next patch. It also points out that the documentation for '{latesttag}' is not quite accurate, since it says "most recent global tag" (singular). I assume it is too radical of a change to convert it to a list of strings. At least ':' is currently a reserved character in tag names.

convert: improve support for unusual .gitmodules Previously convert would throw an exception if it encountered a git commit with a .gitmodules file that was malformed (i.e. was missing, but had submodule files, or was malformed). Instead of breaking the convert entirely, let's print error messages and move on.

convert: handle .gitmodules with non-tab whitespaces The old implementation assumed .gitmodules file lines always began with tabs. It can be any whitespace, so lets trim the lines appropriately.

convert: fix bug with converting the same commit twice Convert had a bug where it relied on repo.tip() to be the newly committed commit. This was not the case if the commit already existed in the repository (since repo.commitctx() did nothing, the tip() referenced some random other commit and the revmap got corrupted). This fixes it by using the node returned by repo.commitctx().