storage: introduce a `revlog.reuse-external-delta` config This option goes a bit further and provides a way to get the same behavior as the `re-delta-all` optimisation from `hg debugupgraderepo`. The effect of the option is a bit hard to test as we do not have multiple diff algorithm at hand. However, we at least make sure the code path run.

storage: introduce a `revlog.reuse-external-delta-parent` config As pointed in c59987ab96b4, we had no simple way to get a client to not blindly reuse the delta parent from a bundle. Instead one had to rely on a side effect of the deprecated `format.generaldelta` configuration. We introduce an explicit `revlog.reuse-external-delta-parent` configuration option (default to True) to control this behavior. If the option is not set, `format.generaldelta` still control this behavior. To test the new option, we convert a couple of place where `generaldelta` have been used for its side effects.

merge with stable

py3: convert return values of inspect.getabsfile() to bytes It's weird that python docs for inspect does not mention getabsfile(). Differential Revision: https://phab.mercurial-scm.org/D6033

py3: add two new passing tests found by buildbot Differential Revision: https://phab.mercurial-scm.org/D6032

py3: make contrib/debugshell.py work with Python 3 I changed default mercurial installation of my personal laptop to one installed with python 3.7. debugshell is one of the extension which I have enabled and it was failing. This patch makes debugshell works with Python 3. I found that chg does not work with python 3. Differential Revision: https://phab.mercurial-scm.org/D6031

absorb: let scmutil.cleanupnodes() take care of setting phase Differential Revision: https://phab.mercurial-scm.org/D6036

absorb: use scmutil.cleanupnodes() also when obsmarkers are disabled A side-effect of this is the new warning in the test case, but the warning is valid, so I don't think that's a problem. Differential Revision: https://phab.mercurial-scm.org/D6035

absorb: use scmutil.cleanupnodes() so operation gets set The operation is useful for e.g. `hg obslog` output. Differential Revision: https://phab.mercurial-scm.org/D6034

test: follow-up on 1c4d6ab2ecb8, stabilize test-remotefilelog-bgprefetch.t In 1c4d6ab2ecb8, I've added some sleeps after about half of the calls to `hg debugwaitonrepack` but it seems the other calls are also flaky as catched by our CI: https://ci.octobus.net/job/MercurialPy2/299/console. Add sleeps after all calls in order to be safe.

tests: add more wildcards to test-extdiff.t This test has been flakey recently on Windows, but it appears to be the same scenario as 88d4477ac4f6.

branchmap: prevent reading the file twice through different iterators Otherwise, test-static-http.t breaks. Differential Revision: https://phab.mercurial-scm.org/D6028

remotefilelog: fix format str, blobsize isn't always a #, can be "(missing)" Differential Revision: https://phab.mercurial-scm.org/D6025

remotefilelog: do not specify an explicit version for repack Differential Revision: https://phab.mercurial-scm.org/D6024

test: generate the `test-sparse-revlog` artifact when slow-test is allowed The `test-sparse-revlog.t` logic requires a large bundle to be generated. This bundle can be reused from one run to the next but its initial generation is slow. With this patch, if the bundle is missing and slow tests are permitted, the bundle will be generated during the test run. This should ensure that CI run this test.

runtest: also update slow test timeout during `#if` clauses For a `#if slow` test to be useful, we need the test timeout to be increased. Without this, the slow section would likely be killed before it finish.

runtest: move slow timeout process earlier in the `_hghave` method Before this changesets, early returns might prevent this logic to apply. It seem safer to run it sooner.

runtest: extract the logic that update timeout for slow tests We want to use the "slow" test logic not only for "#require" clauses but also in "#if" clauses. For this to be useful we need the logic to bump the timeout in at least two spots. The first step it to factor it out.

tests: increase timeout for slow test Test case `test-sparse-revlog.t` need some artifact (a bundle) build before it can run. The artifact is expensive to build, but can be reused from one run to the other. We are about to update that test to make the artifact building automatic if `--allow-slow-tests` is passed. However, we need a bump the timeout a bit to make sure the artifact building as time to finish. We could maybe teach run-tests.py how to directly handle such artifacts. However since there is only one of them for now, this seems premature. There are also some room to speed up the bundle creation for test-sparse-revlog.t

merge with stable

rewriting: add an option for rewrite commands to use the archived phase Using the archived phase for cleanup provide the same effect than stripping, but in a faster, append-only way. We keep the feature experimental for now until it gets a bit more testing.

strip: introduce a soft strip option This is the first user-accessible way to use the archived phase introduced in 4.8. This implements a feature discussed during the Stockholm sprint, using the archived phase for hiding changesets. The archived phase behaves exactly as stripping: changesets are no longer visible, but pulling/unbundling them will make then reappear. The only notable difference is that unlike hard stripping, soft stripping does not affect obsmarkers. The next changeset will make use of the archived phase for history rewriting command. However, having a way to manually trigger the feature first seems a necessary step before exposing users to this phase; there is a way to un-archived changesets (unbundling), so there must be a way to archive them again. Adding a flag to strip is a good way to provide access to the feature without taking a too big risk on the final UI we want. The flag is experimental so it won't be exposed by default. Using the archived phase is faster and less traumatic for the repository than actually stripping changesets.

branchcache: move loading of branch names and nodes into it's own function This will help me in implementing lazy loading of the branchcache in upcoming patches. Differential Revision: https://phab.mercurial-scm.org/D6023

bundle2: don't send "shared" requirement when cloning from a share Differential Revision: https://phab.mercurial-scm.org/D5985

tests: demonstrate failure when cloning from a share via bundle2 Differential Revision: https://phab.mercurial-scm.org/D5984

mq: disable qrecord during histedit (issue5981) qrecord during histedit may lead to deadlock-like situations. qpop will throw an error on called during histedit even after qrecord-ing those changes. This patch makes qrecord to abort on histedit. Differential Revision: https://phab.mercurial-scm.org/D5997

committablectx: move status-related methods closer together The modified()/added()/removed()/deleted() clearly belong very close to status(). I separated them in committablectx by the new p[12]copies() methods. This brings the close again. Sorry about the churn. Differential Revision: https://phab.mercurial-scm.org/D5996

tests: add test for hg-test-mode emacs code This is just coverage for the compilation-mode support, but that was enough of a hassle that I wanted to have it covered somehow. Test methodology is _extremely_ cargo-culted from the test for compilation-mode in emacs, so I still have no idea what I'm doing. Differential Revision: https://phab.mercurial-scm.org/D6003

hghave: add check for GNU emacs Differential Revision: https://phab.mercurial-scm.org/D6002

contrib: also linkify tracebacks in compilation output when using hg-test-mode Differential Revision: https://phab.mercurial-scm.org/D6001

contrib: add compilation-mode linking for our test output These regular expressions will cause compilation-mode buffers in emacs to link to source when there are check-code errors in the output of a .t test. In the true tradition of this file, I also have no idea what I'm doing. Differential Revision: https://phab.mercurial-scm.org/D6000

diff: make sure we output stat even when --git is not passed (issue4037) (BC) Before this patch, `hg diff --stat` will give an empty output. It will not show the stat information. I debugged and found that the underlying code does not return the diff header and due to that, other code paths fails to parse that as a diff. I looked into why we don't return diff headers in quiet mode and found the behavior is from 8f8bb77d560e70bcc95577e4dfa877df18d876ab which does not have any mention about why it is done. We also show the diff headers in git, so I think it's fine showing diff header in normal diff in quiet mode. Differential Revision: https://phab.mercurial-scm.org/D6007