import-checker: drop workaround for pure modules

policy: drop custom importer for pure modules

parsers: switch to policy importer # no-check-commit

mpatch: switch to policy importer

diffhelpers: switch to policy importer # no-check-commit

bdiff: switch to policy importer # no-check-commit

base85: switch to policy importer

osutil: switch to policy importer "make clean" is recommended to test this change, though C API compatibility should be preserved.

policy: add helper to import cext/pure module These functions are sysstr API since __import__() and getattr() hate byte strings on Python 3. There's a minor BC, which is ImportError will be raised if invalid HGMODULEPOLICY is specified. I think this is more desired behavior. We're planning to add strict checking for C API compatibility. This patch includes the stub for it.

demandimport: strictly check missing locals argument locals may be an empty dict.

localrepo: mark walk convenience method as deprecated (API)

debugcommands: use repo[None].walk instead of repo.walk

cmdutil: use repo[None].walk instead of repo.walk

largefiles: use repo[None].walk instead of repo.walk

parsers: add version to help detect breaking binary changes

osutil: add version to help detect breaking binary changes See the previous patch for why.

mpatch: add version to help detect breaking binary changes

diffhelpers: add version to help detect breaking binary changes

base85: add version to help detect breaking binary changes

bdiff: add version to help detect breaking binary changes Previously, we have no way to detect if a compiled .so file could be used or not, and blindly load it if it exists. Usually we carefully maintain compatibility of .so and fallback to pure code gracefully. But if we stick to the rules, certain nice changes will be impossible to make in a clean way. This patch adds a "version" constant to the module so we can detect inconsistency and take appropriate actions (warn, abort, fallback to pure, run make automatically) in module loader.

obsmarker: add an experimental flag controlling "operation" recording It seems better to introduce the experiment behind a flag for now as there are multiple concerns around the feature: * Storing operation increase the size of obsolescence markers significantly (+10-20%). * It performs poorly when exchanging markers (cannot combine command names, command name might be unknown remotely, etc)

run-tests: remove references to Python 2.6 These are the obvious ones. There is tons of code in this file implementing features from unittest that weren't present in Python 2.6. But that's for other patches.

dirstate: mark {begin,end}parentchange as deprecated (API)

merge: migrate to context manager for changing dirstate parents