localrepo: automatically load lfs extension when required (BC) If an unrecognized requirement is present (possibly due to an unloaded extension), the user will get an error message telling them to go to https://mercurial-scm.org/wiki/MissingRequirement for more info. And some requirements clearly map to known extensions shipped by Mercurial. This commit teaches repository loading to automatically map requirements to extensions. We implement support for loading the lfs extension when the "lfs" requirement is present. This behavior feels more user-friendly to me and I'm having trouble coming up with a compelling reason to not do it. The strongest argument I have against is that - strictly speaking - requirements are general repository features and there could be N providers of that feature. e.g. in the case of LFS, there could be another extension implementing LFS support. And the user would want to use this non-official extension rather than the built-in one. The way this patch implements things, the non-official extension could be missing and Mercurial would load the official lfs extension, leading to unexpected behavior. But this feels like a highly marginal use case to me and doesn't outweigh the user benefit of "it just works." If someone really wanted to e.g. use a custom LFS extension, they could prevent the built-in one from being loaded by either defining "extensions.lfs=/path/to/custom/extension" or "extensions.lfs=!", as the automatic extension loading only occurs if there is no config entry for that extension. Differential Revision: https://phab.mercurial-scm.org/D4711

lfs: add repository feature denoting the use of LFS Whether LFS is enabled seems like a useful feature to expose. This will also facilitate some future work around LFS feature compatibility. Differential Revision: https://phab.mercurial-scm.org/D4710

localrepo: define "features" on repository instances (API) There are a handful of attributes/methods on repository instances that describe the behavior of the repository. Furthermore, there is an unbound set of repository descriptors that we may wish to expose. For example, an extension may wish to add a descriptor and have monkeypatched functions look for the presence of an attribute before taking actions. This commit introduces a "features" mechanism to allow repositories to self-advertise an arbitrary set of strings that describe repository behavior or capabilities. We implement basic support for advertising a few features to give an idea of what I want to use this for. Differential Revision: https://phab.mercurial-scm.org/D4709

localrepo: support writing shared file (API) Now that we can create a shared repository via creation options, we can handle other special actions related to share at repo creation time as well. One of the things we do after creating a shared repository is write out a .hg/shared file containing the list of additional things to share. Of which only "bookmarks" is supported. We add a creation option to hold the set of additional items to share. If items are defined, we write out the .hg/shared file at repo creation time. As part of this, we no longer hold the repo lock when writing the file. I'm pretty sure we don't care about the tiny race condition window. I'm also pretty sure the reason we used the lock was because the vfs auditor on the repo instance complained otherwise. Since the repo creation code doesn't have an audited vfs, we don't need to appease it. Because we no longer need to tell the post share hook what items are shared, the "bookmarks" argument to that function has been dropped, incurring an API change. Differential Revision: https://phab.mercurial-scm.org/D4708

localrepo: support shared repo creation Previously, hg.share() had its own logic for creating a new repository on the filesystem. With the recent introduction of the createopts dict for passing options to influence repository creation, it is now possible to consolidate the repo creation code for both the normal and shared use cases. This commit teaches the repo creation code in localrepo to recognize when we're creating a shared repo and to act appropriately. Meaningful behavior should be identical. However, there are a few subtle changes: * The .hg/requires file is written out in sorted order (rather than having share-related requirements appended at end). * The .hg directory is created with notindexed=True when a shared repo is being created. Differential Revision: https://phab.mercurial-scm.org/D4707

localrepo: validate directories before creating any There is no meaningful change in behavior because wdir would already exist in the case where we raised RepoError. But I think the code is easier to read if we do all validation first then take actions with side-effects. Differential Revision: https://phab.mercurial-scm.org/D4706

localrepo: add missing join() Differential Revision: https://phab.mercurial-scm.org/D4705

revlog: use proper version comparison during verify Verify appears to want to compare the changelog's revlog version number with the version number of filelogs and error if they are different. But what it was actually doing was comparing the full 32-bit header integer, which contains 2 shorts: 1 for the revlog version number and 1 for feature flags. This commit tweaks the verification code so it only looks at the version number component of the header and emits a warning if they differ. The new code is more robust because it accounts for future revlog version numbers without them needing to be special cased. Differential Revision: https://phab.mercurial-scm.org/D4704

filelog: stop proxying checksize() (API) This was only used by verify code. And the check using it is now implemented as part of verifyintegrity(). The method is unused and is revlog-centric, which means it isn't appropriate for the file storage interface. So remove it. Differential Revision: https://phab.mercurial-scm.org/D4703

filelog: remove version attribute (API) This was only used by verify code. The check it was used for is now implemented as part of the verifyintegrity() implementation. The attribute is now unused, is revlog-specific, and isn't appropriate to be exposing on the file storage interface. So drop it. Differential Revision: https://phab.mercurial-scm.org/D4702

verify: start to abstract file verification Currently, the file storage interface has a handful of attributes that are exclusively or near-exclusively used by repo verification code. In order to support verification on non-revlog/alternate storage backends, we'll need to abstract verification so it can be performed in a storage-agnostic way. This commit starts that process. We establish a new verifyintegrity() method on revlogs and expose it to the file storage interface. Most of verify.verifier.checklog() has been ported to this new method. We need a way to represent verification problems. So we invent an interface to represent a verification problem, invent a revlog type to implement that interface, and use it. The arguments to verifyintegrity() will almost certainly change in the future, once more functionality is ported from the verify code. And the "revlogv1" version check is very hacky. (The code in verify is actually buggy because it is comparing the full 32-bit header integer instead of just the revlog version short. I'll likely fix this in a subsequent commit.) Differential Revision: https://phab.mercurial-scm.org/D4701

unionrepo: remove _constructmanifest() It is unused after a previous refactor. Spotted in D4641. Differential Revision: https://phab.mercurial-scm.org/D4700

merge with stable

encoding: remove unnecessary lambdas from _encodingfixers They have been unnecessary since 1a3a08b5d4d5 (encoding: remove workaround for locale.getpreferredencoding(), 2017-05-13). Also rename the variable since "fixer" sounds like a function. Differential Revision: https://phab.mercurial-scm.org/D4743

py3: cast exception to bytes In order to appease Python 3. Differential Revision: https://phab.mercurial-scm.org/D4733

py3: cast exception to bytes This was raising a TypeError on Python 3 and preventing most (all?) wireprotov2 commands from working. Differential Revision: https://phab.mercurial-scm.org/D4731

py3: remove a couple of superfluous calls to pycompat.rapply() These places can only be strings.

py3: byteify an inline python test extension # skip-blame for b'' prefixing

py3: conditionalize access to socketserver.ForkingMixIn This is no longer exported on platforms that don't support forking, as of 3.6. https://github.com/python/cpython/commit/aadff9bea61a2fc9f4cf0f213f0ee50fc54d6574

convert: fix a file descriptor leak test-check-code flagged this after I changed this line for something unrelated.

merge with stable

revlog: catch more specific exception in shortest() Since revlog._partialmatch() catches RevlogError coming from cext and re-raises AmbiguousPrefixLookupError, catching RevlogError here seems less correct. Differential Revision: https://phab.mercurial-scm.org/D4735

py3: update missing module list in test-check-py3-compat.t for Windows

py3: add b'' prefixes to wire protocol test Otherwise the CBOR encoder fails on Python 3 due to lacking support for encoding str/unicode. # skip-blame just some b'' prefixes Differential Revision: https://phab.mercurial-scm.org/D4734

py3: use pycompat.strkwargs() Otherwise we get an error attempting to dispatch a command with arguments because we're passing a dict with bytes keys. Differential Revision: https://phab.mercurial-scm.org/D4732

py3: ensure _start_response() is called with system string This was preventing HTTP 500's from being sent in Python 3. Differential Revision: https://phab.mercurial-scm.org/D4730

py3: convert arguments, cwd and env to native strings when spawning subprocess This keeps Windows happy.

py3: apply byteskwargs to contrib/perf

py3: un-byteify strings around os.system() and os.devnull in contrib/perf

py3: work around the lack of sys.maxint in contrib/perf

py3: switch contrib/perf from xrange to pycompat.xrange

py3: handle sysstr conversion around get/set attr in contrib/perf

py3: proxy posixfile objects to re-add a useful 'name' attribute on Windows This file object is used in the vfs layer, so there are many errors like this: ... File "mercurial\localrepo.py", line 2569, in savecommitmessage return self.pathto(fp.name[len(self.root) + 1:]) TypeError: 'int' object is not subscriptable It looks like the 'name' value is actually the fileno() value, and the documentation says the name parameter to PyFile_FromFd() is ignored. [1] I tried just assigning the attribute after osutil.posixfile() returns, but that crashes saying that it's read-only. [1] https://docs.python.org/3.6/c-api/file.html

py3: don't use os.getcwdb() on Windows to avoid DeprecationWarnings See also ac32685011a3.

py3: rename pycompat.getcwd() to encoding.getcwd() (API) We need to avoid os.getcwdb() on Windows to avoid DeprecationWarnings, and we need encoding.strtolocal() to encode the result of os.getcwd().

py3: whitelist two more passing tests Caught by the ratchet, but initially only the non-legacy path of test-clone-uncompressed.t was passing. That required the preceding patch. Differential Revision: https://phab.mercurial-scm.org/D4729

keepalive: be more careful about self._rbuf when calling super impls In Python 3, HTTPResponse implements read() in terms of readinto(), which was calling back into our readinto(), which duplicates self._rbuf if it's not empty. Before calling into super's read(), ensure self._rbuf is empty. Inheritance is bad, and undocumented self-use of your public API is one of many reasons. Differential Revision: https://phab.mercurial-scm.org/D4728

wireprotov2: teach changesetdata to fetch ancestors until depth For shallow clone, it is useful to specify a starting node and tell the server to send up to N ancestors from that starting point. This enables the server to perform the DAG walk without the client having to discover the base/stop node(s) first. This commit implements support for said queries on the changesetdata command. Differential Revision: https://phab.mercurial-scm.org/D4621

wireprotov2: allow multiple fields to follow revision maps The *data wire protocol commands emit a series of CBOR values. Because revision/delta data may be large, their data is emitted outside the map as a top-level bytestring value. Before this commit, we'd emit a single optional bytestring value after the revision descriptor map. This got the job done. But it was limiting in that we could only send a single field. And, it required the consumer to know that the presence of a key in the map implied the existence of a following bytestring value. This commit changes the encoding strategy so top-level bytestring values in the stream are explicitly denoted in a "fieldsfollowing" key. This key contains an array defining what fields that follow and the expected size of each field. By defining things this way, we can easily send N bytestring values without any ambiguity about their order. In addition, clients only need to know how to parse ``fieldsfollowing`` to know if extra values are present. Because this breaks backwards compatibility, we've bumped the version number of the wire protocol version 2 API endpoint. Differential Revision: https://phab.mercurial-scm.org/D4620

wireprotov2: advertise set of valid values for requestable fields changesetdata, manifestdata, and filedata all allow the caller to specify what data fields to request. Data fields are extensible and may evolve over time. In order to prevent clients from making requests for fields that are not available, the client needs to know what fields are available. This commit teaches the server to declare a set of "valid values" for wire protocol command arguments. That set of values is exposed in the command's capabilities descriptor. The changesetdata, manifestdata, and filedata commands all declare their set of available "fields." Differential Revision: https://phab.mercurial-scm.org/D4619

wireprotov2: expose rich arguments metadata Now that we internally store rich metadata about arguments, it makes sense to make that metadata available to the client. This will allow clients to validate outgoing command requests before they are sent over the wire. Strictly speaking, we should bump the wire protocol version for this change since it is backwards incompatible. But no client-side code touches the arguments map and I don't want to incur the work. Differential Revision: https://phab.mercurial-scm.org/D4618

wireprotov2: advertise recognized path filter prefixes While the wire protocol doesn't yet support it, we'll eventually have commands that accept narrow patterns to specify the set of files relevant to a command. For security and performance reasons, only specific filter types are allowed. This commit teaches the server to advertise the set of allowed filter types. By doing so, clients can e.g. validate user-specified patterns against the server's abilities without having to send a command to retrieve data. Having the data in the capabilities data structure will also serve as a check against unwanted BC. Differential Revision: https://phab.mercurial-scm.org/D4616

wireprotov2: declare command arguments richly Previously, we declared command arguments with an example of their value. After this commit, we declare command arguments as a dict of metadata. This allows us to define the value type, whether the argument is required, and provide default values. This in turn allows us to have nice things, such as less boilerplate code in individual commands for validating input and assigning default values. It should also make command behavior more consistent as a result. Test output changed slightly because I realized that the "fields" argument wasn't being consistently defined as a set. Oops! Other test output changed because of slight differences in code performing type validation. Differential Revision: https://phab.mercurial-scm.org/D4615

chgserver: do not send system() back to client if stdio redirected (issue5992) As the chg client doesn't know server-side stdio redirection, the server shouldn't upcall on "runsystem" request if the stdio streams are redirected. This patch teaches ui to remember the redirection flag, which is updated by the caller right now. Future patches (for default) will add ui methods to manage this flag internally.

chgserver: update comment describing when to fall back to core _runsystem() The condition "output needs to be captured" was moved to the core ui, and removed at fbce78c58f1e "chg: refactor ui.system() to be partly overridden." The next patch will add one more "if" to address the issue 5992.

procutil: compare fd number to see if stdio protection is needed (issue5992) When I wrote this function for commandserver at 69f86b937035, testing object identity was suffice, and I was sloppy enough not to compare fileno() values. However, it doesn't work in chg session because chgserver reopens stdio to apply new buffering mode. This patch partially fixes the issue 5992. Still we have another problem in chgui._runsystem().

test-ssh: show that stdio redirection doesn't work with chg Running tests with --chg doesn't mean all hg invocations are replaced by chg. This patch explicitly adds the test for "chg serve --stdio", which does weird stdio dance.

revset: make heads(commonancestors(x + x^)) be x^, not x Differential Revision: https://phab.mercurial-scm.org/D4742