tests: force a stable hostname in patchbomb tests No visible output changes in this commit because everything is globbed away, but on Python 3 the stable hostname will mean that the headers don't trigger RFC2822 multi-line mode because they'll always be consistently short. Differential Revision: https://phab.mercurial-scm.org/D4295

patchbomb: allow using HGHOSTNAME to force a hostname I'll update run-tests.py to set this globally to stabilize some tests. The variable name is intentionally generic because I suspect we should generalize this to other tests. Differential Revision: https://phab.mercurial-scm.org/D4294

patchbomb: extract function for generating message-id Differential Revision: https://phab.mercurial-scm.org/D4293

rebase: cover restorestatus() by lock to prevent it from being updated To prevent it from being updated by another process `restorestatus()` is moved under lock. Differential Revision: https://phab.mercurial-scm.org/D4282

branchmap: load branchmap as an iterable This avoids reading all the file into memory if the cache turns out to be invalid. Differential Revision: https://phab.mercurial-scm.org/D4281

perf: time loading branchmap caches Differential Revision: https://phab.mercurial-scm.org/D4280

tests: add conditional output when simplestore extensions is loaded This drops the number of failures with this extension to 3. Differential Revision: https://phab.mercurial-scm.org/D4286

tests: conditionalize extension tests for extra extensions If extra extensions are loaded (e.g. via --extra-config-opt), the tests conditionalized in this commit fail in ways that are dependent on the extensions that are loaded. So let's skip them when that scenario is present. This drops the number of failures for the simplestorerepo.py extension to 4. Differential Revision: https://phab.mercurial-scm.org/D4285

commit: try hard to reuse p1 manifest if nothing changed This is all for commit reproducibility on "hg convert". With this change, p1 manifest is reused if ctx.files() *to be committed* is empty, and if new manifest entry is identical to p1. This is important property for "hg convert" since memctx.files() built from a convert source may be either a) more narrowed thanks to a committed ctx.files() which provides more accurate status, or b) containing redundant files because of sloppy filtering on e.g. octopus merge.

merge: add tests for commit with no content change It isn't easy to say when to reuse the p1 manifest. Basically, that's only when wctx.files() is empty, but we need to know that wctx.files() is not the same as repo['.'].files() after the commit. This patch adds several examples of commits with empty ctx/wctx.files(). I don't think this is exhaustive, but it contains at least one failure mode in which a converted repo result in a different hash. I also note that the manifest revlog does NOT follow the DAG shape of the changelog since p1 manifest is reused if wctx.files() is empty even at merge. I don't know whether it is intentional or not, but it's the behavior since 2011, 301725c3df9a "localrepo: reuse parent manifest in commitctx if no files have changed."