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

diff: use fctx.size() to test empty fctx.size() could have a fast path that does not require loading content.

diff: use fctx.isbinary() to test binary The end goal is to avoid calling fctx.data() when unnecessary. For example, if diff.nobinary=1 and files are binary, the expected behavior is to print "Binary file has changed". That could avoid reading fctx.data() sometimes. This is mainly to enable an external LFS extension to skip expensive binary file loading sometimes (read: most of the time with diff.nobinary=1 and diff.text=0), without any behavior changes to mercurial (i.e. whether a file is LFS or not does not change any behavior, LFS could be 100% transparent to users).

pycompat: extract helper to raise exception with traceback It uses "raise excobj, None, tb" form which I think is simpler and more useful than "raise exctype, args, tb".

largefiles: make sure debugstate command is populated before wrapping Copied the hack from 869d660b8669, which seemed the simplest workaround. Perhaps debugcommands.py should have its own commands table.

check-code: ignore re-exports of os.environ in encoding.py These are valid uses of os.environ.

check-code: exclude demandimport.py and policy.py from Python 3 checks These modules can't depend on pycompat.py, which means we have to write Py3 hacks in them.

check-code: rewrite py3 exclusion pattern with negative lookahead I want to add more patterns, but negative lookbehind requires patterns of the same length so not useful.

cleanup: remove useless re-raises of KeyboardInterrupt KeyboardInterrupt is no longer a subclass of Exception since Python 2.5. https://docs.python.org/2/whatsnew/2.5.html#pep-352-exceptions-as-new-style-classes

make: drop deprecated rule to process temporary copy of pure modules Pure modules never be copied to mercurial/ since 511a4384b033.

help: describe about choice of :prompt as a fallback merge tool explicitly "merge-tools" help topic has described that the merge of the file fails if no tool is found to merge binary or symlink, since c77f6276c9e7 (or Mercurial 1.7), which based on (already removed) MergeProgram wiki page. But even at that revision, and of course now, merge of the file doesn't fail automatically for binary/symlink. ":prompt" (or equivalent logic) is used, if there is no appropriate tool configuration for binary/symlink.

wix: only one KeyPath is allowed per Component

dirstate: optimize walk() by using match.visitdir() We already have the logic for restricting directory walks in match.visitdir() that we use for treemanifests. We should take advantage of it when walking the working copy as well. This speeds up "hg st -I rootfilesin:." on the Firefox repo from 0.587s to 0.305s on warm disk (and much more on cold disk). More time is spent reading the dirstate than walking the working copy after. I tried to find scenarios where calling match.visitdir() would be a noticeable overhead, but I couldn't find any. I encourage the reader to try for themselves, since this is performance-critical code.

match: optimize visitdir() for patterns matching only root directory Because _rootsanddirs() returns a list of directories to visit recursively and a list of directories to visit non-recursively. For patterns such as 'rootfilesin:foo/bar', we clearly need to visit the directory foo/bar, but we also need to visit its parents. The method therefore uses util.dirs() to find the parent directories of 'foo/bar'. That method does not include the root directory, but since we obviously need to visit the root directory, we always added '.' to the set of directories to visit non-recursively. The visitdir() method had special handling to consider set(['.']) to mean that no includes had been specified and would thus visit all directories. However, when the pattern is 'rootfilesin:.', set(['.']) is actually the real set of directories to visit and the special handling of that set meant that all directories got visited instead of just the root directory. The fix is simple: add '.' to the set of parent directories in _rootsanddirs() and stop treating set(['.']) specially. This makes hg files -r . -I rootfilesin:. in a treemanifest version of the Firefox repo go from 1.5s to 0.26s on warm disk (and a *much* bigger improvement on cold disk). Note that the -I is necessary for no good reason. We just haven't optimized visitdir() for regular (non-include, non-exclude) patterns yet.

rebase: don't update state dict same way for each root The update statement does not depend on anything in the loop, so just move it before the loop and do it once. There are no cases where update would happen 0 times before (and 1 now); the function returns early in all such cases.

forget: access status fields by name, not index

demandimport: add urwid.command_map to ignore list The useful pudb debugger can be used with Mercurial, but its import of urwid fails when demandimport is enabled. Add urwid.command_map to the ignore list so pudb can be used with hg without disabling all of demandimport.

outgoing: run on filtered repo outgoing has been using an unfiltered repo since fe67107094fd (discovery: outgoing pass unfiltered repo to findcommonincoming (issue3776), 2013-01-28). If I'm reading code and history correctly, it should be safe to run _outgoing() on a filtered repo since c5456b64eb07 (discovery: run discovery on filtered repository, 2015-01-07). By running _outgoing() on a filtered repo, we can also remove the workaround there for ignoring filtered revisions.

manifest: remove check for non-contexts in _dirmancache It looks like the _dirmancache has contained only manifest contexts since d79c141fdf41 (manifest: remove usages of manifest.read, 2016-11-10).

bundle: factor the 'getchangegroup' out The call in the two branches is identical, so we can just issue it outside of the conditional.

bundle: avoid reset of the 'outgoing' variable We have a cleaner way to achieve the same effect. Not resetting the variable will help us to simplify the code.

changegroup: deprecate 'getlocalchangroup' (API) We have 'getchangegroup' with a shorter name for the exactly same feature. Now that all users are gone we can formally deprecate it.

tests: directly 'getchangegroup' It is identical to 'getlocalchangegroup' with a shorter name.

exchange: directly 'getchangegroup' It is identical to 'getlocalchangegroup' with a shorter name.