debuginstall: check C extensions only if they are loadable per policy This check is useless in pure installation and I want to make it directly import C extension modules.

osutil: proxy through util (and platform) modules (API) See the previous commit for why. Marked as API change since osutil.listdir() seems widely used in third-party extensions. The win32mbcs extension is updated to wrap both util. and windows. aliases.

mpatch: proxy through mdiff module See the previous commit for why.

bdiff: proxy through mdiff module See the previous commit for why. mdiff seems a good place to host bdiff functions. bdiff.bdiff was already aliased as textdiff, so we use it.

base85: proxy through util module I'm going to replace hgimporter with a simpler import function, so we can access to pure/cext modules by name: # util.py base85 = policy.importmod('base85') # select pure.base85 or cext.base85 # cffi/base85.py from ..pure.base85 import * # may re-export pure.base85 functions This means we'll have to use policy.importmod() function in place of the standard import statement, but we wouldn't want to write it every place where C extension modules are used. So this patch makes util host base85 functions.

mdiff: move re-exports to top This style seems more common in our codebase.

test-commit-interactive-curses: remove unused import of parsers

strip: make tree stripping O(changes) instead of O(repo) The old tree stripping logic iterated over every tree revlog in the repo looking for commits that had revs to be stripped. That's very inefficient in large repos. Instead, let's look at what files are touched by the strip and only inspect those revlogs. I don't have actual perf numbers, since internally we don't use a true treemanifest, but simply iterating over hundreds of thousands of revlogs takes many, many seconds, so this should help tremendously when stripping only a few commits.

strip: move tree strip logic to it's own function This will allow external extensions to modify tree strip behavior more precisely.

manifest: remove unused property _oldmanifest The last use seems to have gone away in 7c7d845f8b64 (manifest: make manifestlog use it's own cache, 2016-11-10).

py3: convert key to str to make kwargs.pop work in mq The keys are passed here and there as unicodes and our transformer make things bytes. Due to that, mq was not poped and this results in error on Py3. Here we abuse r'' to make that str on Python 3.

py3: convert kwargs' keys to str before passing in cmdutil.getcommiteditor

diff: add a fast path to avoid loading binary contents When diffing binary contents, with certain configs, we can show "Binary file <name> has changed" without actual content. That allows a fast path where we could avoid providing actual binary contents. Note: in that case we still need to test if two contents are the same, that's done by using "filectx.cmp", which could have its own fast path.

diff: correct binary testing logic This seems to be more correct given the table drawn in the previous patch. Namely, "losedatafn" and "opts.git" are removed, "not opts.text" is added. - losedatafn: diff output (binary) should not be affected by "losedatafn" - opts.git: binary testing is helpful for detecting a fast path in the next path. the fast path can also be used if opts.git is False - opts.text: if it's set, we should treat the content as non-binary

diff: draw a table about binary diff behaviors The table should make it easier to reason about future changes.