revlog: use struct.Struct instances for slight performance wins Differential Revision: https://phab.mercurial-scm.org/D32

revlog: micro-optimize the computation of hashes Differential Revision: https://phab.mercurial-scm.org/D31

hgweb: re-implement followlines UI selection using buttons This changeset attempts to solve two issues with the "followlines" UI in hgweb. First the "followlines" action is currently not easily discoverable (one has to hover on a line for some time, wait for the invite message to appear and then perform some action). Second, it gets in the way of natural line selection, especially in filerevision view. This changeset introduces an additional markup element (a <button class="btn-followlines">) alongside each content line of the view. This button now holds events for line selection that were previously plugged onto content lines directly. Consequently, there's no more action on content lines, hence restoring the "natural line selection" behavior (solving the second problem). These buttons are hidden by default and get displayed upon hover of content lines; then upon hover of a button itself, a text inviting followlines section shows up. This solves the first problem (discoverability) as we now have a clear visual element indicating that "some action could be perform" (i.e. a button) and that is self-documented. In followlines.js, all event listeners are now attached to these <button> elements. The custom "floating tooltip" element is dropped as <button> elements are now self-documented through a "title" attribute that changes depending on preceding actions (selection started or not, in particular). The new <button> element is inserted in followlines.js script (thus only visible if JavaScript is activated); it contains a "+" and "-" with a "diff-semantics" style; upon hover, it scales up. To find the parent element under which to insert the <button> we either rely on the "data-selectabletag" attribute (which defines the HTML tag of children of class="sourcelines" element e.g. <span> for filerevision view and <tr> for annotate view) or use a child of the latter elements if we find an element with class="followlines-btn-parent" (useful for annotate view, for which we have to find the <td> in which to insert the <button>). On noticeable change in CSS concerns the "margin-left" of span:before pseudo-elements in filelog view that has been increased a bit in order to leave space for the new button to appear between line number column and line content one. Also note the "z-index" addition for "annotate-info" box so that the latter appears on top of new buttons (instead of getting hidden). In some respect, the UI similar to line commenting feature that is implemented in popular code hosting site like GitHub, BitBucket or Kallithea.

localrepo: cache types for filtered repos (issue5043) Python introduces a reference cycle on dynamically created types via __mro__, making them very easy to leak. See https://bugs.python.org/issue17950. Previously, repo.filtered() created a type on every invocation. Long-running processes (like `hg convert`) could call this function thousands of times, leading to a steady memory leak. Since we're Unable to stop the leak because this is a bug in Python, the next best thing is to contain it. This patch adds a cache of of the dynamically generated repoview/filter types on the localrepo object. Since we only generate each type once, we cap the amount of memory that can leak to something reasonable. After this change, `hg convert` no longer leaks memory on every revision. The process will likely grow memory usage over time due to e.g. larger manifests. But there are no leaks.

convert: transcode CVS log messages by specified encoding (issue5597) Converting from CVS to Mercurial assumes that CVS log messages in "cvs rlog" output are encoded in UTF-8 (or basic Latin-1). But cvs itself is usually unaware of encoding of log messages, in practice. Therefore, if there are commits, of which log message is encoded in other than UTF-8, log message of corresponded revisions in the converted repository will be broken. To avoid such broken log messages, this patch transcodes CVS log messages by encoding specified via "convert.cvsps.logencoding" configuration. This patch accepts multiple encoding for convenience, because "multiple encoding mixed in a repository" easily occurs. For example, UTF-8 (recent POSIX), cp932 (Windows), and EUC-JP (legacy POSIX) are well known encoding for Japanese.

fsmonitor: execute setup procedures only if dirstate is already instantiated Before this patch, reposetup() of fsmonitor executes setup procedures for dirstate, even if it isn't yet instantiated at that time. On the other hand, dirstate might be already instantiated before reposetup() intentionally (prefilling by chg, for example, see bf3af0eced44 for detail). If so, just discarding already instantiated one in reposetup() causes issue. To resolve both issues above, this patch executes setup procedures, only if dirstate is already instantiated. BTW, this patch removes "del repo.unfiltered().__dict__['dirstate']", because it is responsibility of the code path, which causes instantiation of dirstate before reposetup(). After this patch, using localrepo.isfilecached() should avoid creating the corresponded entry in repo.unfiltered().__dict__.

fsmonitor: centralize setup procedures for dirstate

fsmonitor: avoid needless instantiation of dirstate Using repo.local() instead of util.safehasattr(repo, 'dirstate') also avoids executing setup procedures for remote repository (including statichttprepo). This is reason why this patch also removes a part of subsequent comment, and try/except for AttributeError at accessing to repo.wvfs.

journal: use wrapfilecache instead of wrapfunction on func of filecache wrapfilecache() on filecache-ed property works more strictly than wrapfunction() directly on func() of filecache.

journal: execute setup procedures for already instantiated dirstate If dirstate is instantiated before reposetup() of journal extension, it doesn't have "journalstorage" property, even if it is instantiated via wrapdirstate() wrapping repo.dirstate(), because wrapdirstate() works as same as original one before marking repo as "journal"-ing in reposetup(). This issue can be reproduced by running test-journal.t or test-journal-share.t with fsmonitor-run-tests.py. On the other hand, just discarding already instantiated dirstate in reposetup() prevents chg from filling dirstate before reposetup() (see bf3af0eced44 for detail). Therefore, this patch executes setup procedures for already instantiated dirstate explicitly in reposetup(). To centralize setup procedures for dirstate, this patch also factors them out from wrapdirstate().

localrepo: add isfilecached to check filecache-ed property is already cached isfilecached() encapsulates internal implementation of filecache-ed property. "name in repo.unfiltered().__dict__" or so can't be used for this purpose, because corresponded entry in __dict__ might be discarded by repo.invalidate(), repo.invalidatedirstate() or so (fsmonitor does so, for example). This patch makes isfilecached() return not only whether filecache-ed property is already cached, but also already cached value (or None), in order to avoid subsequent access to cached object via "repo.NAME", which prevents main Mercurial procedure after reposetup() from validating cache.

sslutil: check for missing certificate and key files (issue5598) Currently, sslutil._hostsettings() performs validation that web.cacerts exists. However, client certificates are passed in to the function and not all callers may validate them. This includes httpconnection.readauthforuri(), which loads the [auth] section. If a missing file is specified, the ssl module will raise a generic IOException. And, it doesn't even give us the courtesy of telling us which file is missing! Mercurial then prints a generic "abort: No such file or directory" (or similar) error, leaving users to scratch their head as to what file is missing. This commit introduces explicit validation of all paths passed as arguments to wrapsocket() and wrapserversocket(). Any missing file is alerted about explicitly. We should probably catch missing files earlier - as part of loading the [auth] section. However, I think the sslutil functions should check for file presence regardless of what callers do because that's the only way to be sure that missing files are always detected.

match: override matchfn instead of __call__ for consistency The matchers that were recently moved into core from the sparse extension override __call__, while the previously existing matchers override matchfn. Let's switch to the latter for consistency.

match: express anypats(), not prefix(), in terms of the others When I added prefix() in 9789b4a7c595 (match: introduce boolean prefix() method, 2014-10-28), we already had always(), isexact(), and anypats(), so it made sense to write it in terms of them (a prefix matcher is one that isn't any of the other types). It's only now that I realize that it's much more natural to define prefix() explicitly (it's one that uses path: patterns, roughly speaking) and let anypats() be defined in terms of the others. Remember that these methods are all used for determining which fast paths are possible. anypats() simply means that no fast paths are possible (it could be called complex() instead). Further evidence is that rootfilesin:some/dir does not have any patterns, but it's still considered to be an anypats() matcher. That's because anypats() really just means that it's not a prefix() matcher (and not always() and not isexact()). This patch thus changes prefix() to return False by default and anypats() to return True only if the other three are False. Having anypats() be True by default also seems like a good thing, because it means forgetting to override it will lead only to performance bugs, not correctness bugs. Since the base class's implementation changes, we're also forced to update the subclasses. That change exposed and fixed a bug in the differencematcher: for example when both its two input matchers were prefix matchers, we would say that the result was also a prefix matcher, which is incorrect, because e.g "path:dir - path:dir/foo" no longer matches everything under "dir" (which is what prefix() means).

match: make nevermatcher an exact matcher and a prefix matcher The m.isexact() and m.prefix() methods are used by callers to determine whether m.files() can be used for fast paths. It seems safe to let callers to any fast paths it can that rely on the empty m.files().

revset: define successors revset This revset returns all successors, including transit nodes and the source nodes (to be consistent with existing revsets like "ancestors"). To filter out transit nodes, use `successors(X)-obsolete()`. To filter out divergent case, use `successors(X)-divergent()-obsolete()`. The revset could be useful to define rebase destination, like: `max(successors(BASE)-divergent()-obsolete())`. The `max` is to deal with splits. There are other implementations where `successors` returns just one level of successors, and `allsuccessors` returns everything. I think `successors` returning all successors by default is more user friendly. We have seen cases in production where people use 1-level `successors` while they really want `allsuccessors`. So it seems better to just have one single revset returning all successors by default to avoid user errors. In the future we might want to add `depth` keyword argument to it and for other revsets like `ancestors` etc. Or even build some flexible indexing syntax [1] to satisfy people having the depth limit requirement. [1]: https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-July/101140.html

sparse: shorten try..except block in updateconfig() It now only covers refreshwdir(). This is what importfromfiles() does. I think it is the more appropriate behavior.

sparse: clean up updateconfig() * Use context manager for wlock * Rename oldsparsematch to oldmatcher * Always call parseconfig() because parsing an empty string yields the same result as the old code

sparse: move config updating function into core As part of the move, the ui argument was dropped. Additional fixups will be made in a follow-up commit.

dirstate: expose a sparse matcher on dirstate (API) The sparse extension performs a lot of monkeypatching of dirstate to make it sparse aware. Essentially, various operations need to take the active sparse config into account. They do this by obtaining a matcher representing the sparse config and filtering paths through it. The monkeypatching is done by stuffing a reference to a repo on dirstate and calling sparse.matcher() (which takes a repo instance) during each function call. The reason this function takes a repo instance is because resolving the sparse config may require resolving file contents from filelogs, and that requires a repo. (If the current sparse config references "profile" files, the contents of those files from the dirstate's parent revisions is resolved.) I seem to recall people having strong opinions that the dirstate object not have a reference to a repo. So copying what the sparse extension does probably won't fly in core. Plus, the dirstate modifications shouldn't require a full repo: they only need a matcher. So there's no good reason to stuff a reference to the repo in dirstate. This commit exposes a sparse matcher to dirstate via a property that when looked up will call a function that eventually calls sparse.matcher(). The repo instance is bound in a closure, so it isn't exposed to dirstate. This approach is functionally similar to what the sparse extension does today, except it hides the repo instance from dirstate. The approach is not optimal because we have to call a proxy function and sparse.matcher() on every property lookup. There is room to cache the matcher instance in dirstate. After all, the matcher only changes if the dirstate's parents change or if the sparse config changes. It feels like we should be able to detect both events and update the matcher when this occurs. But for now we preserve the existing semantics so we can move the dirstate sparseness bits into core. Once in core, refactoring becomes a bit easier since it will be clearer how all these components interact. The sparse extension has been updated to use the new property. Because all references to the repo on dirstate have been removed, the code for setting it has been removed.

sparse: use self instead of repo.dirstate "self" here is the dirstate instance. I'm pretty confident that self and repo.dirstate will be the exact same object. So remove a dependency on repo by just looking at self.

sparse: move code for importing rules from files into core This is a pretty straightforward port. Some code cleanup was performed. But no major changes to the logic were made. I'm not a huge fan of this function because it does multiple things. I'd like to get things into core first to facilitate refactoring later. Please also note the added inline comment about the oddities of writeconfig() and the try..except to undo it. This is because of the hackiness in which the sparse matcher is obtained by various consumers, notably dirstate. We'll need a massive refactor to address this. That refactor is effectively blocked on having the sparse dirstate hacks live in core.

sparse: refactor activeprofiles into a generic function (API) activeprofiles() is a special case of a more generic function. Furthermore, that generic function is essentially already implemented inline in the sparse extension. So, refactor activeprofiles() to a generic activeconfig(). Change the only consumer of activeprofiles() to use it. And have the inline implementation in the sparse extension use it.

check-code: prohibit `if False` antipattern Differential Revision: https://phab.mercurial-scm.org/D20

convert: remove `if False` block This code has never run since its introduction on July 18th, 2007. It's time for it to go. Differential Revision: https://phab.mercurial-scm.org/D19

filterpyflakes: move self-test into test file This will avoid a false positive on an upcoming check-code rule. Differential Revision: https://phab.mercurial-scm.org/D18

test-subrepo: demonstrate a status problem when merge deletes a file At the interactive update prompt, if (c) is chosen and then followed by `hg rm`, both `status -R` and `status -S` show the file as 'R', and `files -R` shows no files (OK, because explicitly removed files aren't supposed to be listed). If `rm` follows selecting (c), then both flavors of `status` list the file as '!', and `files -R` lists the missing file. So somehow, the (d) option has followed a third path.

subrepo: make the output references to subrepositories consistent Well, mostly. The annotation on subrepo functions tacks on a parenthetical to the abort message, which seems reasonable for a generic mechanism. But now all messages consistently spell out 'subrepository', and double quote the name of the repo. I noticed the inconsistency in the change for the last commit.

subrepo: consider the parent repo dirty when a file is missing This simply passes the 'missing' argument down from the context of the parent repo, so the same rules apply. subrepo.bailifchanged() is hardcoded to care about missing files, because cmdutil.bailifchanged() is too. In the end, it looks like this addresses inconsistencies with 'archive', 'identify', blackbox logs, 'merge', and 'update --check'. I wasn't sure how to implement this in git, so that's left for someone more familiar with it.

archival: flag missing files as a dirty wdir() in the metadata file (BC) Since the identify command adds a '+' for missing files, it's reasonable that this does too. Perhaps the node field's hex value should be p1+p2 for merges?