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

diff: add --from and --to flags as clearer alternative to -r -r I think it was mistake to let the `-r` flag accept two revisions in `hg diff` in 98633e60067c (Support for 0, 1, or 2 diff revs, 2005-05-07). The command clearly acts on two revisions and having a single flag to indicate which those are is unclear. It got worse when it started accepting revsets as input. This patch introduces `--from` and `--to` flags, each taking a single revision and each defaulting to the working copy. That means that `hg

commandserver: handle IOError related to flushing of streams After dispatch, without chg we have handling of flushing of streams and exception handling related to it. The exception handling part is important because there can be exceptions when flushing fout or ferr. One such case is in `test-basic.t` which was failing on python3+chg without this patch as this handling was missing from chg. Failure can be seen at https://foss.heptapod.net/octobus/mercurial-devel/-/jobs/128399 Honestly I am not sure which one of `chgserver.py` or `commandserver.py` the change should go in. Differential Revision: https://phab.mercurial-scm.org/D9517

tests: conditionalize output in test-ssh.t with chg+py3 Because of our wrapping around sys.std* and python3 internal buffering, the output order changes. The change in order seems like harmless because just few lines above the same command is run which results in same output. This makes `test-ssh.t` works with --chg on python 3. Differential Revision: https://phab.mercurial-scm.org/D9502