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.