merge: refactor code to advise fsmonitor in separate function merge.update() is quite hard to understand, found this an easy win. The end goal is to have better organized merge and mergestate handling and then fix some related bugs. Differential Revision: https://phab.mercurial-scm.org/D8740

mergestate: document what mergestate._results is for Understanding that dict is important for understanding how mergestate is performing operations on dirstate. Differential Revision: https://phab.mercurial-scm.org/D8739

mergestate: rename a helpless variable name to bit helpful one The old variable name `r` makes it ~impossible to understand what does it mean. One can only understand that after going to callers and hoping that its documented there. I also documented return value of the function involved while I was there. Differential Revision: https://phab.mercurial-scm.org/D8738

mergestate: remove unnecessary recordactions() from mergestate class This function is updating dirstate which sounds like not something which a method on mergestate class should do. Also this just calls another function. Lets directly call that function and remove this reducing mergestate responsibility a bit. There was single caller which is updated. Differential Revision: https://phab.mercurial-scm.org/D8737

mergestate: document mergestate records in an organized way This makes clear which mergestate record is used for what and group them based on how they are used right now. Differential Revision: https://phab.mercurial-scm.org/D8719

mergestate: remove unused unsupported related mergestate records I tried to find users of this but was unable to find. Seems like RECORD_OVERRIDE is doing for what they were used before. Differential Revision: https://phab.mercurial-scm.org/D8718

mergestate: add comments about couple of record types and minor reorder I am trying to divide the records into certain groups and then have dedicated objects for them. Taking baby steps in that direction. Differential Revision: https://phab.mercurial-scm.org/D8717

mergestate: remove unrequired RECORD_RESOLVED_OTHER record This was introduced in last cycle however while working on refactoring mergestate, I realized it's unncessary. This will break users who did a merge using previous version, did this kind of storage and before commiting updated the mercurial version. Differential Revision: https://phab.mercurial-scm.org/D8716

mergestate: rename addpath() -> addpathonflict() to prevent confusion addpath() seems to imply that we are adding a new path/entry to the mergestate. Differential Revision: https://phab.mercurial-scm.org/D8715

windows: don’t set `softspace` attribute in `winstdout` Python 2 file objects have the `softspace` attribute (https://docs.python.org/2/library/stdtypes.html#file.softspace), which is used by the print statement to track its internal state. The documentation demands from file-like objects only that the attribute is writable and initialized to 0. Method `file.write()` sets it to 0, but this is not documented. Historically, sys.stdout was replaced by an instance of the `winstdout` class, so it needed to behave exactly the same (the softspace fix was introduced in 705278e70457). Nowadays we don’t replace sys.stdout and don’t use the print statement on `winstdout` instances, so we can safely drop it.

windows: handle file-like objects without isatty() method Copying the function is not nice, but moving around stuff to avoid the circular import didn’t seem to be worth the effort.

exchange: check actually missing revs for obsolete / unstable revs (issue6372) The previous code was using `outgoing.ancestorsof`, which was originally called `outgoing.missingheads` although not containing the missing heads. This confusion was probably the reason why the buggy code was written. The actually outgoing changesets are stored in `outgoing.missing`. By checking all outgoing changesets, we avoid the problem and can show the list of all obsolete or unstable changesets, which is more helpful for the user.

tests: test that push doesn’t complain about unstable changesets if no changes When there’re no outgoing changes, push doesn’t complain about unstable changesets. There is currently a bug (see issue6372) that causes that there is an abort on push when the outgoing changes contain another changeset even if that is not obsolete or unstable. A test case and fix for that is sent in the next patch.

diff: move no-eol text constant to a common location Differential Revision: https://phab.mercurial-scm.org/D8763

revert: fix interactive reverting of end-of-file newline changes The chunk reversal used by `revert -i` in Curses mode was not taking this case into account. Differential Revision: https://phab.mercurial-scm.org/D8762

phabricator: clarify the multiple heads/roots error message for phabsend As pointed out in followup feedback for c1c922391314, it's confusing to say there are multiple items and then only list one. Differential Revision: https://phab.mercurial-scm.org/D8761

error: normalize "unresolved conflicts" error messages with a custom class Differential Revision: https://phab.mercurial-scm.org/D8713

error: unify the error message formats for 'rebase' and 'unshelve' Differential Revision: https://phab.mercurial-scm.org/D8730

debugcommands: create new debugantivirusrunning command This writes the EICAR test file to .hg/cache, in an attempt to trigger an AV scanner's scanning engine. This should let us (in theory) detect some cases when a user's slowness is a result of AV scanning. Differential Revision: https://phab.mercurial-scm.org/D8353

windows: always work around EINVAL in case of broken pipe for stdout / stderr In 29a905fe23ae, I missed the fact that the `winstdout` class works around two unrelated bugs (size limit when writing to consoles and EINVAL in case of broken pipe) and that the latter bug happens even when no console is involved. When writing a test for this, I realized that the same problem applies to stderr, so I applied the workaround for EINVAL to both stdout and stderr. The size limit is worked around in the same case as before (consoles on Windows on Python 2). For that, I changed the `winstdout` class.

tests: make pipes / PTYs non-inheritable in test-stdio.py A following patch requires that to test closing the receiving end of the pipe / PTYs. Even for existing tests, it might be safer to make the lifetime of the pipes / PTYs as short as possible.

util: enhance `nullcontextmanager` to be able to return __enter__ result This makes its functionality and signature equivalent to Python 3.7’s contextlib.nullcontext().

windows: augment docstring of `winstdout` class

discovery: change users of `outgoing.missingheads` to `outgoing.ancestorsof` The attribute `missingheads` was recently renamed to `ancestorsof`, as it, despite the old name, doesn’t contain the missing heads but the changesets that were requested (including ancestors) for the outgoing operation. Changing all the users enables to print a warning if the old name is used. There is a good chance that some of the users are buggy because of the old name. Changing them to use the new name makes it more obvious that they are buggy. All users need to be reviewed for bugs. When sending patches for fixing them, the change will be more obvious without having to explain again and again the discrepancy of the old attribute name and what it actually contained.