setup: tweak error message for Python 3 We now have beta support for Python 3. In my opinion, it isn't yet stable enough to allow `pip install Mercurial` to work with Python 3 out of the box: we don't want people accidentally using Mercurial with Python 3 just yet. But I do think we should be more friendly about informing people of their options. This commit tweaks the error message that users see when running setup.py with Python 3. We instruct them about the current level of Python 3 support, point them at the wiki for more info, and give them instructions on how to bypass the check. As part of this, I also changed which version value is printed, as we were printing a named tuple before.

setup: remove set and dict comprehensions Yuya observed in a recent review that it is worthwhile to keep setup.py parseable with Python 2.6 so a useful error message is seen when attempting to run with Python 2.6. This commit removes a set and dict comprehension so setup.py is parseable with Python 2.6.

branchcache: don't verify all nodes while writing nodes are verified either when they are added or used. In case of commits. we will load the whole branchmap, only verify nodes for the branch on which we are committing and then we write. However before this patch, writing the branchmap was validating all the nodes whereas it should not. This patch fixes that. Differential Revision: https://phab.mercurial-scm.org/D6290

setup: properly package distutils in py2exe virtualenv builds Our in-repo py2exe packaging code uses virtualenvs for managing dependencies. An advantage of this is that packaging is more deterministic and reproducible. Without virtualenvs, we need to install packages in the system Python install. Packages installed by other consumers of the system Python could leak into the Mercurial package. A regression from this change was that py2exe packages contained the virtualenv's hacked distutils modules instead of the original distutils modules. (virtualenv installs a hacked distutils module because distutils uses relative path lookups that fail when running from a virtualenv.) This commit introduces a workaround so py2exe packaging uses the original distutils modules when running from a virtualenv. With this change, `import distutils` no longer fails from py2exe builds produced from a virtualenv. This fixes the regression. Furthermore, we now include all distutils modules. Before, py2exe's module finding would only find modules there were explicitly referenced in code. So, we now package a complete copy of distutils instead of a partial one. This is even better than before. # no-check-commit foo_bar function name

narrow: also warn when not deleting untracked or ignored files Differential Revision: https://phab.mercurial-scm.org/D6265

setdiscovery: fix a few typos Differential Revision: https://phab.mercurial-scm.org/D6263

copies: delete debug message about "unmatched files new in both" Same reasoning as previous patch. Differential Revision: https://phab.mercurial-scm.org/D6251

copies: delete debug message about changes since common ancestor Same reasoning as previous patch. Differential Revision: https://phab.mercurial-scm.org/D6250

copies: delete debug message about search limit I'm about to rewrite mergecopies() and this message will no longer be emitted then. Let's remove the message now to remove a distraction from that patch. Differential Revision: https://phab.mercurial-scm.org/D6249

copies: move early return for "no copies" case a little earlier We can return before the block that prints debug messages. That block will not be run anyway when there are no copies. Differential Revision: https://phab.mercurial-scm.org/D6248

copies: fix up "fullcopy" with missing entries from "diverge" Similar to the previous patch, but this doesn't even affect tests. It does affect tests if you change them to turn on debug logging. I'm fixing it here so reviewers of the later rewrite patch can hard-code debug logging to be on and more easily compare test results. Differential Revision: https://phab.mercurial-scm.org/D6247

copies: fix up "fullcopy" with missing entries from "copy" This is just a workaround similar to the previous one. It will make it easier to follow later patches. Differential Revision: https://phab.mercurial-scm.org/D6246

merge: remove workaround for issue5020 As I explained in the previous commit, I think the filtering added there is a better fix for the issue, so the workaround from 41f6af50c0d8 (merge: fix crash on criss cross merge with dir move and delete (issue5020), 2017-01-31) should no longer be needed. Differential Revision: https://phab.mercurial-scm.org/D6245

copies: don't include copies that are not in source in directory move I've been working on a rewrite of mergecopies(). I compared the output of the rewritten version with the current version. I noticed that between FIREFOX_NIGHTLY_59_END and FIREFOX_BETA_60_BASE in the mozilla-unified repo, there were many copies that the current version detected that the rewritten version did not. One example was js/src/gc/Iteration.h -> js/src/gc/PublicIterators.h. Then I realized that js/src/gc/Iteration.h doesn't even exist in FIREFOX_NIGHTLY_59_END. This patch adds a filtering step for the "fullcopy" dict. It turns out that that change also affects the test for issue5020 in test-merge-criss-cross.t. The 'dm' action no longer happens there. At first I thought that the test case change meant that this patch was broken, but I think it's actually correct tha the 'dm' action should not happen there. The result of the bid merge is still the same. I suspect this filtering is a better solution for the issue than 41f6af50c0d8 (merge: fix crash on criss cross merge with dir move and delete (issue5020), 2017-01-31). I also suspect that it was broken just a few months earlier by a005c33d0bd7 (mergecopies: add logic to process incomplete data, 2016-10-04). Note that bid merge had been enabled for a few years at that point, since 19903277f035 (merge: use bid merge by default (BC), 2014-10-01). This patch is still just a workaround. It will be cleaned up soon (with the rewrite of mergecopies()). But doing this in a separate patch makes later patches easier to understand and gives a place to explain why this is changing. Differential Revision: https://phab.mercurial-scm.org/D6244

tests: add test for issue5343 (grafting with copies) It seems that issue5353 resulted in a lot of tests in test-graft.t, but the bug actually reported in that issue didn't get a test case. This patch adds one for the "move" and one for the "copy" version of it. I also added a "copy+modify" case, to show what should be a merge conflict. I didn't add one for the "backwards" version of it since the comment says that that was already covered by previous work. The tests added by this patch show the broken behavior (the bug is still open). I suspect the results returned from mergecopies() are not expressive enough to fix this issue: it has a dict for copies to merge with, but that can only give one more filename, but here we need two (one for the path on the remote side and one for the path in the merge base). I want to have it tested anyway since I'm about to refactor mergecopies(). Differential Revision: https://phab.mercurial-scm.org/D6242

chistedit: use context manager to set verbose ui I'm still not exactly sure why this is necessary -- perhaps setting it unconditionally would leak this setting in chg invocations. Regardless, this would have looked very out of place as compared to how this setting is done everywhere else, so at least for the sake of style, let's be consistent with the rest of the codebase.

setdiscovery: stop limiting the number of local head we initially send In our testing this limitation provides now real gain and instead triggers pathological discovery timing for some repository with many heads. See inline documentation for details. Some timing below: Mozilla try repository, (~1M revs, ~35K heads), discovery between 2 clones with 100 head missing on each side before: ! wall 1.492111 comb 1.490000 user 1.450000 sys 0.040000 (best of 20) ! wall 1.813992 comb 1.820000 user 1.700000 sys 0.120000 (max of 20) ! wall 1.574326 comb 1.573500 user 1.522000 sys 0.051500 (avg of 20) ! wall 1.572583 comb 1.570000 user 1.520000 sys 0.050000 (median of 20) after: ! wall 1.147834 comb 1.150000 user 1.090000 sys 0.060000 (best of 20) ! wall 1.449144 comb 1.450000 user 1.330000 sys 0.120000 (max of 20) ! wall 1.204618 comb 1.202500 user 1.146500 sys 0.056000 (avg of 20) ! wall 1.194407 comb 1.190000 user 1.140000 sys 0.050000 (median of 20) pypy (~100 heads, 317 heads) discovery between clones with only 42 common heads before: ! wall 0.031653 comb 0.030000 user 0.030000 sys 0.000000 (best of 25) ! wall 0.055719 comb 0.050000 user 0.040000 sys 0.010000 (max of 25) ! wall 0.038939 comb 0.039600 user 0.038400 sys 0.001200 (avg of 25) ! wall 0.038660 comb 0.050000 user 0.040000 sys 0.010000 (median of 25) after: ! wall 0.018754 comb 0.020000 user 0.020000 sys 0.000000 (best of 49) ! wall 0.034505 comb 0.040000 user 0.030000 sys 0.010000 (max of 49) ! wall 0.019631 comb 0.019796 user 0.018367 sys 0.001429 (avg of 49) ! wall 0.019132 comb 0.020000 user 0.020000 sys 0.000000 (median of 49) Private repository (~1M revs, ~3K heads), discovery from a strip subset, about 100 changesets to be pulled. before: ! wall 1.837729 comb 1.840000 user 1.790000 sys 0.050000 (best of 20) ! wall 2.203468 comb 2.200000 user 2.100000 sys 0.100000 (max of 20) ! wall 2.049355 comb 2.048500 user 2.002500 sys 0.046000 (avg of 20) ! wall 2.035315 comb 2.040000 user 2.000000 sys 0.040000 (median of 20) after: ! wall 0.136598 comb 0.130000 user 0.110000 sys 0.020000 (best of 20) ! wall 0.330519 comb 0.330000 user 0.260000 sys 0.070000 (max of 20) ! wall 0.157254 comb 0.155500 user 0.123000 sys 0.032500 (avg of 20) ! wall 0.149870 comb 0.140000 user 0.110000 sys 0.030000 (median of 20) Same private repo, discovery between two clone with 500 different heads on each side: before: ! wall 2.372919 comb 2.370000 user 2.320000 sys 0.050000 (best of 20) ! wall 2.622422 comb 2.610000 user 2.510000 sys 0.100000 (max of 20) ! wall 2.450135 comb 2.450000 user 2.402000 sys 0.048000 (avg of 20) ! wall 2.443896 comb 2.450000 user 2.410000 sys 0.040000 (median of 20) after: ! wall 0.625497 comb 0.620000 user 0.570000 sys 0.050000 (best of 20) ! wall 0.834723 comb 0.820000 user 0.730000 sys 0.090000 (max of 20) ! wall 0.675725 comb 0.675500 user 0.628000 sys 0.047500 (avg of 20) ! wall 0.671614 comb 0.680000 user 0.640000 sys 0.040000 (median of 20)

peer: introduce a limitedarguments attributes When set to True, it signal that the peer cannot receive too larges arguments and that algorithm must adapt. This should only be True for http peer that does not support argument passed as "post". This will be useful to unlock better discovery performance in the next changesets. I am using a dedicated argument because this is not really a usual "capabilities" things. An alternative approach would be to adds a "large-arguments" to all peer, but the http peers. That seemed a bit too hacky to me.

verify: also check full manifest validity during verify runs Before this changes, `hg verify` only checked if a manifest revision existed and referenced the proper files. However it never checked the manifest revision content itself. Mercurial is expecting manifest entries to be sorted and will crash otherwise. Since `hg verify` did not attempted a full restoration of manifest entry, it could ignore this kind of corruption. This new check significantly increases the cost of a `hg verify` run. This especially affects large repository not using `sparse-revlog`. For now, this is hidden behind the `--full` experimental flag.

verify: introduce an experimental --full flag The flag currently has no effect, see next changeset for details. We introduce the flag as experimental to keep the freedom of changing our mind on the final UI. Note: this patch highlight a small but in `hg help`. An option section is generated even if no option are visible.

verify: introduce a notion of "level" Some checks are slower than others, to help the user to run the checks he needs, we are about to introduce new flag to select faster vs deeper runs. This put the scaffolding in place to do this.

tests: split out separate test for issue5020 The test was added to the existing setup in 41f6af50c0d8 (merge: fix crash on criss cross merge with dir move and delete (issue5020), 2017-01-31). I'm about to make a change that affects that test and it's much easier to follow if the test case for issue5020 is a separate test case. The separate test case is based on what mpm provided in comment 12 on the issue. `hg diff -r 41f6af50c0d8^ tests/test-merge-criss-cross.t` after this patch is pretty small (besides the added test). It's probably easier for reviewers to look at that than to try to understand the diff itself (I don't understand it). Differential Revision: https://phab.mercurial-scm.org/D6243

tests: avoid a rename/delete conflict when updating in test-narrow-update.t After the upcoming rewrite of mergecopies(), this test would otherwise (accurately) start warning about "inside/f1 was deleted and renamed". Differential Revision: https://phab.mercurial-scm.org/D6254

tests: delete unused function in test-rename-merge2.t Differential Revision: https://phab.mercurial-scm.org/D6253

tests: make merge conflicts explicit in `hg annotate` tests We were using `true` as merge tool. I think it makes the test easier to understand if we make the conflicts explcit. It also papered over a conflict that shouldn't have been a conflict (just a bug in copy tracing). I've marked that "BROKEN". Differential Revision: https://phab.mercurial-scm.org/D6252

narrow: make warning about possibly dirty files respect ui.relative-paths Differential Revision: https://phab.mercurial-scm.org/D6264

merge: forgot to pull before release These two changes should be part of 5.0, but we are fine leaving them out of the RC.

Added signature for changeset 4a8d9ed86475

Added tag 5.0rc0 for changeset 4a8d9ed86475

merge: default into stable for release candidate

debugdiscovery: include the number of heads in all sets We already displayed information about heads of the common set that are either local or remote heads. We now also do so for heads of the common set that are both local and remote heads too. This is useful because various step in the set discovery algorithm have head specific optimizations.

recover: add a --[no-]verify flag For trivial cases, the cost of the verify run after `hg recover` is getting in the way. In addition for very large repositories, the cost is simply too high to be paid, making `hg recover` an unusable commands. We introduce a --verify flag, set by default. If is automatically associated with a --no-verify flag that one can use to skip the verify step. We might consider changing the default behavior in the future. However this is out of scope for this series.