tests: clarify a comment describing a phabricator test scenario Per review feedback. Differential Revision: https://phab.mercurial-scm.org/D8455

phabricator: ensure that `phabsend` is given a contiguous, linear commit range Supplying a non-linear range was another orphan factory. While in theory there could be a use case for skipping over garbage commits (like adding debugging) and getting the valuable commits extracted out at the same time as posting a review, it seems far more likely that specifying a non-linear range is a user error. This is another case of issue6045, but predates both 0680b8a1992a and 601ce5392cb0. Neither the `--no-amend` case nor resubmitting a previously submitted commit would cause orphans. But for the sake of simplicity and to keep the parents tracked on Phabricator in the proper state, ban missing commits unconditionally. Differential Revision: https://phab.mercurial-scm.org/D8454

merge with stable

automation: support building Python 3 MSI installers This is very similar to what we just did for Inno. Differential Revision: https://phab.mercurial-scm.org/D8484

automation: support building Python 3 Inno installers The core packaging code now supports building Python 3 installers using PyOxidizer. Let's teach the automation code to invoke it so that we produce both Python 2 and Python 3 based exe installers. When publishing the artifacts, the Python 3 versions are preferred over the Python 2 versions given their higher weight (10 versus 9). This may be a controversial change. But I think making Python 3 the default is warranted, as it is the future. The Python 2 installers are still fully supported and can be installed should issues with Python 3 arise. Differential Revision: https://phab.mercurial-scm.org/D8483

automation: add extra arguments when building Inno These were being fed into the template expansion but not being used. This meant --version was not getting set when it should have been. Differential Revision: https://phab.mercurial-scm.org/D8482

packaging: add -python2 to Windows installer filenames We just taught the Windows installers to produce Python 3 variants built with PyOxidizer. Our plan is to publish both Python 2 and Python 3 versions of the installers for Mercurial 5.4. This commit teaches the Inno and WiX installers to add an optional string suffix to the installer name. On Python 2, that suffix is "-python2." We reserve the existing name for the Python 3 installers, which we want to make the default. Differential Revision: https://phab.mercurial-scm.org/D8479