windows: continue looking at `%HOME%` for user config files with py3.8+ The `%HOME%` variable is explicitly called out in `hg help config` as a location that is consulted when reading user files, but python stopped looking at it when expanding '~' in py3.8+.[1] Restore that old functionality by copying in the old implementation (and simplifying it to just use bytes). It could be simplfied further, since only '~' is passed, but I'm not sure yet if we need to make this a generic utility function on Windows. There are other uses of `os.path.expanduser()`, but this is the only case I know of that documents `%HOME%` usage. (The reason for removing it was that it typically isn't set, but it actually is set in MSYS and PowerShell, and `%HOME%` and `%USERPROFILE%` are different in MSYS. I could be convinced to just replace all uses with this as a general utility, so we don't have to think too hard about BC.) [1] https://bugs.python.org/issue36264 Differential Revision: https://phab.mercurial-scm.org/D9559

run-tests: configure the environment to expand `~` properly with Windows py38+ This was causing tests to point to the actual home path on the system, not the test defined one. Differential Revision: https://phab.mercurial-scm.org/D9558

run-tests: fix `HGTESTEXTRAEXTENSIONS` with py3 Since `extensions` was a str and `section` bytes, it never populated anything. If it had, it would have put bytes into the environment dictionary that is all str. As everything starts and ends as str, remove the incomplete attempt at byteification. It doesn't appear that we had any test coverage of this bit of code, so also add a non-extension config to make sure it is filtered out properly. Differential Revision: https://phab.mercurial-scm.org/D9557

rhg: use persistent nodemap when available … for node ID → revision number lookups, instead on linear scan in a revlog. Differential Revision: https://phab.mercurial-scm.org/D9520

persistent-nodemap: properly ignore non-existent `.nd` data file This code was meant to handle the case of a nodemap docket file pointing to a nodemap data file that doesn’t exist (anymore), but most likely caused an `UnboundLocalError` exception instead when `data` was used on the next line without being defined. This case is theoretically possible with a race condition between two hg processes, but is hard to reproduce or test: * Process A reads a docket file and finds a UID in it that points to a given data file name. * Process B decides that this same data file needs compacting. It writes a new one with a different UID, overwrites the docket file, then removes the old data file. * Only then process A tries to a open a file that doesn’t exist anymore. Differential Revision: https://phab.mercurial-scm.org/D9533

docs: prefer `hg diff --from/--to` over `-r` This patch includes updating away from the broken `hg diff -r 'date(...)'` (see not in previous patch). Differential Revision: https://phab.mercurial-scm.org/D9555