stream: double check that self.vfs is *not* in the vfsmap The stream clone logic allows for writing any content to any file under various vfs. This is *not* suitable for *vfs*, since writing in `.hg/` directly allow to modify the configuration and is a great and simple gateway for remote code execution. Differential Revision: https://phab.mercurial-scm.org/D10905

dirstate: split dirstatemap in its own file The dirstate file is large enough and the dirstatemap is quite insulated logic already. Differential Revision: https://phab.mercurial-scm.org/D10934

run-tests: stop writing a `python3` symlink pointing to python2 Having `python3` actually pointing to `python2` is bad. So we stop doing so. In addition we need to re-introduce a `python` executable since some of the script really need to be able to say "current python" in their shbang. For example, `hghave` is one of such script. The faulty changes where introduced by c102b704edb5. Differential Revision: https://phab.mercurial-scm.org/D10943

check-code: stop forbidding return code result There is no explication of what is the intend of that check and what is the alternative. I suspect this comes from the transition to the "unified test" format circa 2010. With the non zero return explicitly listed in the output explicit $? checking became Redundant. However there is valid use case for checking $? so I am dropping this check. Differential Revision: https://phab.mercurial-scm.org/D10994

run-tests: avoid an early return To fix the "python3 pointing to python2" we will also need to create a "python" pointer. So we will need to create multiple pointer. So we need to stop using early return. We replace the early return with a loop and a continue, since the next changeset will introduce that loop anyway. Differential Revision: https://phab.mercurial-scm.org/D10942

run-tests: clarify pyexename assignement That assignement is wrong, we clarify that it is wrong before starting to fix it. This will make the fix clearer. Differential Revision: https://phab.mercurial-scm.org/D10941

run-tests: factor appdata out This is a gratuitous readability change. Differential Revision: https://phab.mercurial-scm.org/D10940

run-tests: unroll a non-so-one-liner This is shorter and clearer. Differential Revision: https://phab.mercurial-scm.org/D10939

run-tests: unroll a non-so-one-liner This is shorter and clearer. Differential Revision: https://phab.mercurial-scm.org/D10938

testing: fix _timeout_factor With `--debug`, `run-tests.py` set the timeout to 0... that breaks the logic in `mercurial.testing`. Differential Revision: https://phab.mercurial-scm.org/D10937