revbranchcache: factor logic to write names and revs in separate functions Before this patch, the write function was so populated with upto 4 level of indentation, it was hard to understand what's going on. Differential Revision: https://phab.mercurial-scm.org/D6291

tests: make log style a little easier to read in test-copytrace-heuristics.t Revision numbers are much shorter and easier to read (especially compared to the full nodeids that were used here), so I switched to that. That's also what almost all the commands used (e.g. `hg rebase -s . -d 1`). I updated the two instances that used nodeids. I also made some other little cleanups to the log templates. Differential Revision: https://phab.mercurial-scm.org/D6279

tests: avoid cryptic nodeids in tests/test-rename-merge1.t These two nodeids had not been part of any output before, so one can't know which revision they refer to without adding something like `hg log` before them. It turned out that '.^' was equivalent for both of them, so that's what I replaced them with. Differential Revision: https://phab.mercurial-scm.org/D6280

tests: defines aliases for `hg log` calls in test-copytrace-heuristics.t This also makes the test cases more consistent since a few had missed the ":" in "changeset:" that the others used. Differential Revision: https://phab.mercurial-scm.org/D6278

rust-discovery: implementing and exposing stats() This time, it's simple enough that we can do it in all layers in one shot. Differential Revision: https://phab.mercurial-scm.org/D6233

rust-discovery: cpython bindings for the core logic As previously done with the ancestors submodule, testing for the bindings is provided from Python on a trivial case. Differential Revision: https://phab.mercurial-scm.org/D6232

rust-discovery: starting core implementation Once exposed to the Python side, this core object will avoid costly roundtrips with potentially big sets of revisions. This changeset implements the core logic of the object only, i.e., manipulation of the missing, common and undefined set-like revision attributes. Differential Revision: https://phab.mercurial-scm.org/D6231

rust-dagops: roots Unsuprisingly, the algorithm is much easier than for heads, provided we work on a set in the first place. To improve the signature, a trait for set-likes object would be useful, but that's not an immediate concern. Differential Revision: https://phab.mercurial-scm.org/D6230

rust-dagops: range of revisions This is a Rust implementation for what reachableroots2() does if includepath is True. The algorithmic details and performance notes are included in the documentation comment. Our main use case for now is a Rust counterpart of the partialdiscovery object, so we don't really need bindings yet. Differential Revision: https://phab.mercurial-scm.org/D6229

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.