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.

bundle2: handle compression in _forwardchunks _forwardchunks is used to compensate for getbundle protocol deficits. Since it transparently decodes the payload, it also needs to remove the corresponding compression parameter in case the server decides to send one. This the wire protocol part of issue 5990. Differential Revision: https://phab.mercurial-scm.org/D6182

changelog: parse copy metadata if available in extras This lets read back the copy metadata we just started writing. There are still many places left to teach about getting the copy information from the changeset, but we have enough ({file_copies}, specifically) that we can add it now and have some test coverage of it. Differential Revision: https://phab.mercurial-scm.org/D6186

copies: add config option for writing copy metadata to file and/or changset This introduces a config option that lets you choose to write copy metadata to the changeset extras instead of to filelog. There's also an option to write it to both places. I imagine that may possibly be useful when transitioning an existing repo. The copy metadata is stored as two fields in extras: one for copies since p1 and one for copies since p2. I may need to add more information later in order to make copy tracing faster. Specifically, I'm thinking out recording which files were added or removed so that copies._chaincopies() doesn't have to look at the manifest for that. But that would just be an optimization and that can be added once we know if it's necessary. I have also considered saving space by using replacing the destination file path by an index into the "files" list, but that can also be changed later (but before the feature is ready to release). Differential Revision: https://phab.mercurial-scm.org/D6183

revsetbenchmark: add some simpler revset for heads and roots This revset might leverage compiled code in the future so lets start to track them.

repoview: flag `server.view` as experimental Ideally, the non-experimental version of `experimental.extra-filter-revs` will cover the use case for `server.view=immutable` well enough than having to have this dedicated configuration. Since `server.view` is not part of any release, I would prefer to have it marked as experimental to avoid having it to support it for ever.

repoview: move subsettable in a dedicated module The dictionary got moved in `branchmap` to avoid import cycle. However, we are about to needs it in repoview too. So we introduce a now module to define that that mapping.

upgrade: support upgrade to/from zstd storage (issue6088) Now that we have an official config option for a shiny format improvement, we better make it simple to migrate to/from it.

compression: introduce an official `zstd-revlog` requirement This requirement supersedes `exp-compression-zstd`. However, we keep support for the old requirement. Strictly speaking, we do not need to add a new requirement, there are no logic change making "new" repo incompatible with mercurial client using a version that support `exp-compression-zstd`. The choice to introduce a new requirement is motivated by the following: * The previous requirement was explicitly "experimental". Using it by default could confuse users. * adding support for a hypothetical third compression engine will requires new code, and will comes with its own requirement tool. * We won't use it as the default for a while since I do not think we support zstd on all platform. I can imagine we'll gain another (unrelated but on my default) requirement by the time we turn this zstd by default.

compression: only declare revlog support for available engine Even if we know that an engine support revlog compression, the Mercurial process still won't support it if the compression engine is not available.

branchcache: lazily validate nodes in iteritems() This saves ~0.30 sec on creating a new branch on our internal repo. Differential Revision: https://phab.mercurial-scm.org/D6236

branchcache: only iterate over branches which needs to be verified Otherwise we loop over all the branches and call _verifybranch() even if not required. Differential Revision: https://phab.mercurial-scm.org/D6240

branchcache: fix the docstring of _verifybranch() Initially the function was designed to support verifying all branches but later I decided to have a separate function. I forget to remove the doc related to that. Thanks to Yuya for spotting this in review. Differential Revision: https://phab.mercurial-scm.org/D6239

branchcache: don't verify while creating a copy The copy will not be mark as verified, so there is no need to verify nodes. Thanks to Yuya who spotted this while reviewing. Differential Revision: https://phab.mercurial-scm.org/D6238

pull: improved message issued in case of failed update When running `hg pull --update`, the update step may fail. Nothing in the error message help to understand the abort is related to the secondary step (update) instead of the primary step (pull). We now add some information to the error message to clarify it comes from the update part. It is useful in various situation (uncommitted changes blocking the update, update to hidden destination, etc...) The pull output is updated from: $ hg pull ../repo-Bob --rev 956063ac4557 --update pulling from ../repo-Bob searching for changes adding changesets adding manifests adding file changes added 2 changesets with 0 changes to 2 files (+1 heads) (2 other changesets obsolete on arrival) abort: filtered revision '6'! to: $ hg pull ../repo-Bob --rev 956063ac4557 --update pulling from ../repo-Bob searching for changes adding changesets adding manifests adding file changes added 2 changesets with 0 changes to 2 files (+1 heads) (2 other changesets obsolete on arrival) abort: cannot update to target: filtered revision '6'! (I am not sure why the actual error, "filtered revision '6'", is not using the more modern format mentioning the obsolescence fate of '6')

pull: deal with locally filtered changeset passed into --rev Nowadays, it is possible to explicitly pull a remote revision that end up being hidden locally (eg: obsoleted locally). However before this patch, some internal processing where crashing trying to resolve a filtered revision. Without this patches, the pull output result a confusing output: $ hg pull ../repo-Bob --rev 956063ac4557 pulling from ../repo-Bob searching for changes adding changesets adding manifests adding file changes added 2 changesets with 0 changes to 2 files (+1 heads) (2 other changesets obsolete on arrival) abort: 00changelog.i@956063ac4557828781733b2d5677a351ce856f59: filtered node!

absorb: aborting if another operation is in progress This increases safety of using absorb by both aborting when another operation is in progress (since the absorption could confuse any other command a lot) and holding the locks throughout the reading of the working directory (for which changes to absorb) and the reading of the repo (for which changes to absorb into). Differential Revision: https://phab.mercurial-scm.org/D6237

repoview: keep the branchmap cache for the `served.hidden` view warm For the same reason we want to keep the cache for the `served` view up to date, we want to also keep the `served.hidden` view up to date. If some processes with a readonly access to the repo needs to access it, we better have the cache warm to avoid computing the same data over and over and over. In most case (no secret changesets), the "served" and "served.hidden" set will be identical and no cache will actually have to be updated.

repoview: introduce a filter for serving hidden changesets There are multiple usecase for being able to explicitly view or pull obsolete from a server. We need to be able to do so without exposing the secret changesets. We introduces a dedicated repository "view" to do so. Way to expose this "view" to the user will come later. To keep a behavior consistent with expected client/server behavior, the general idea is for the obsolete access to be explicitly requested by the code generating the request. In addition, the will be server side configuration to restrict the access to this feature.

repoview: fix conditional around unserved changesets The conditional could lead to wrong computation since we have more unserved changesets than just the "secret" phase. In addition, now that we have efficient caching of phased changesets, we don't need the conditional anymore.

branch: return early if we find an open named branch apart from default The current code builds a list of all the open named branches except default and then bool that. This is mostly fine until you get a repo which has thousands of named branches. Differential Revision: https://phab.mercurial-scm.org/D6211

branchcache: don't verify closed nodes in _branchtip() We only do membership testing there. Differential Revision: https://phab.mercurial-scm.org/D6210

branchcache: don't verify closed nodes in iteropen() We expect that the nodes passed to iteropen() will be verified. We are only testing for membership in closed nodes set, so we don't need to verify the whole closed nodes set. This will speed up calculating branchheads() when there are lot of closed nodes related to other branches. Differential Revision: https://phab.mercurial-scm.org/D6209

branchcache: lazily validate nodes from the branchmap On my personal hg-repository with 365 entries in .hg/cache/branch2, following are the numbers for perfbranchmapload. Before this patch: ! wall 0.000866 comb 0.000000 user 0.000000 sys 0.000000 (best of 2680) ! wall 0.001525 comb 0.000000 user 0.000000 sys 0.000000 (max of 2680) ! wall 0.001107 comb 0.001097 user 0.001086 sys 0.000011 (avg of 2680) ! wall 0.001104 comb 0.000000 user 0.000000 sys 0.000000 (median of 2680) With this patch: ! wall 0.000530 comb 0.000000 user 0.000000 sys 0.000000 (best of 4240) ! wall 0.001078 comb 0.000000 user 0.000000 sys 0.000000 (max of 4240) ! wall 0.000696 comb 0.000693 user 0.000677 sys 0.000017 (avg of 4240) ! wall 0.000690 comb 0.000000 user 0.000000 sys 0.000000 (median of 4240) On our internal repository with ~20k entries in branchcache, I see improvement from 0.125 sec to 0.066 sec which is 47% speed up. The above are the numbers of perfbranchmapload which shows how much time we saved by not validating the nodes. But we need to validate some nodes. Following are timings of some mercurial operations which have speed up because of this lazy validation of nodes: No-op `hg update` on our internal repository (Avg on 4 runs): Before: 0.540 secs After: 0.430 secs Setting a branch name which already exists without --force (Avg of 4 runs): Before: 0.510 secs After: 0.250 secs I ran the ASV performance suite and was unable to see any improvements except there was improvement of perfdirstatewrite() on netbeans which I think was not related. I looked into the commit code, the command which I am trying to speedup, it looks like it uses revbranchcache to update the branchcache. Differential Revision: https://phab.mercurial-scm.org/D6208

branchcache: add functions to validate changelog nodes This patch adds functions to validate closed nodes, validate nodes for a certain branch and for all the branches. These functions will be used in upcoming patches. Differential Revision: https://phab.mercurial-scm.org/D6207

readline: provide styled prompt to readline (issue6070) Differential Revision: https://phab.mercurial-scm.org/D6168

copies: move comment about implementation of mergecopies() to end When you start reading about mergecopies(), you want to know what it is, not that there are different implementations depending on config, so this patch moves that comment to the end. By the way, we don't seem to define what "copytracing" is. I'm just leaving it that way because I don't know what it is myself. It seems to be referred to only on mergecopies() (and not in pathcopies(), for example), so maybe "copytracing" is supposed to be exactly what mergecopies() does? Differential Revision: https://phab.mercurial-scm.org/D6235

remotefilelog: return expected type from copies overrides copies._computeforwardmissing() and copies._computenonoverlap() return sets, so the overrides should also do that. Differential Revision: https://phab.mercurial-scm.org/D6234

changelog: extract a _string_unescape() to mirror _string_escape() We use our own _string_escape() to encode the "extras" field. Then we use codecs.escape_decode() to escape it. But there's also a little workaround for dealing with escaped text that looks like octal numbers since the fix for https://bz.mercurial-scm.org/show_bug.cgi?id=3156. This patch extracts the call to codecs.escape_decode() along with the fix for octal numbers and puts it in a _string_unescape(). It also updates the test to check for the octal-number case from the aforementioned bug. As you may have suspected, I want to be able to reuse this new function later. Differential Revision: https://phab.mercurial-scm.org/D6184

copies: extract function for deciding whether to use changeset-centric algos We'll eventually have a "experimental.copies.read-from=changeset-only" option too and I don't want to spread the logic for determining if we should use changeset-centric of filelog-centric algorithms. Differential Revision: https://phab.mercurial-scm.org/D6163