changelog: load pending file directly When changelogs are written, a copy of the index (or inline revlog) may be written to an 00changelog.i.a file to facilitate hooks and other processes having access to the pending data before it is finalized. The way it works today, the localrepo class loads the changelog like normal. Then, if it detects a pending transaction, it asks the changelog class to load a pending changelog. The changelog class looks for a 00changelog.i.a file. If it exists, it is loaded and internal data structures on the new revlog class are copied to the original instance. The existing mechanism is inefficient because it loads 2 revlog files. The index, node map, and chunk cache for 00changelog.i are thrown away and replaced by those for 00changelog.i.a. The existing mechanism is also brittle because it is a layering violation to access the data structures being accessed. For example, the code copies the "chunk cache" because for inline revlogs this cache contains the raw revision chunks and allows the original changelog/revlog instance to access revision data for these pending revisions. This whole behavior of course relies on the revlog constructor reading the entirety of an inline revlog into memory and caching it. That's why it is brittle. (I discovered all this as part of modifying behavior of the chunk cache.) This patch streamlines the loading of a pending 00changelog.i.a revlog by doing it directly in the changelog constructor if told to do so. When this code path is active, we no longer load the 00changelog.i file at all. The only negative outcome I see from this change is if loading 00changelog.i was somehow facilitating a role. But I can't imagine what that would be because we throw away its data (the index data structures are replaced and inline revision data is replaced via the chunk cache) and since 00changelog.i.a is a copy of 00changelog.i, file content should be identical, so there should be no meaninful file integrity checking at play. I think this was all just sub-optimal code.

cleanup: use set literals We no longer support Python 2.6, so we can now use set literals.

py3: convert date and format arguments str before passing in time.strptime time.strptime() raises ValueError if the arguments are not str. Source Code: https://hg.python.org/cpython/file/3.5/Lib/_strptime.py#l307

py3: convert kwargs' keys to str using pycompat.strkwargs

verify: add a config option to skip certain flag processors Previously, "hg verify" verifies everything, which could be undesirable when there are expensive flag processor contents. This patch adds a "verify.skipflags" developer config. A flag processor will be skipped if (flag & verify.skipflags) == 0. In the LFS usecase, that means "hg verify --config verify.skipflags=8192" will not download all LFS blobs, which could be too large to be stored locally. Note: "renamed" is also skipped since its default implementation may call filelog.data() which will trigger the flag processor.

changegroup: add bundlecaps back Commit 282b288aa20c333c removed the unused bundlecaps argument from the changegroup code. While it is unused in core Mercurial, it was an important feature for the remotefilelog extension because it allowed the exchange layer to communicate to the changegroup packer that this was a shallow repo and that filelogs should not be included. Without bundlecaps, there is currently no other way to pass that information along without a more extensive refactor of exchange, bundle, and changegroup code. This patch backs out the original removal, and merges it with some recent changes to changegroup apis.

flagprocessor: add a fast path when flags is 0 When flags is 0, _processflags could be a no-op instead of iterating through the flag bits.

shelve: make shelvestate use simplekeyvaluefile Currently shelvestate uses line ordering to differentiate fields. This makes it hard for extensions to wrap shelve, since if two alternative versions of code add a new line, correct merging is going to be problematic. simplekeyvaluefile was introduced fot this purpose specifically. After this patch: - shelve will always write a simplekeyvaluefile - unshelve will check the first line of the file for a version, and if the version is 1, will read it in a position-based way, if the version is 2, will read it in a key-value way As discussed with Yuya previously, this will be able to handle old-style shelvedstate files, but old Mercurial versions will fail on the attempt to read shelvedstate file of version 2 with a self-explanatory message: 'abort: this version of shelve is incompatible with the version used in this repo'

shelve: refactor shelvestate loading This is a preparatory patch which separates file reading from the minimal validation we have (like turning version into int and checking that this version is supported). The purpose of this patch is to be able to read statefile form simplekeyvaluefile, which is implemented in the following patch.

extdiff: copy back execbit-only changes to the working directory Some tools like BeyondCompare allow the file mode to be changed. The change was previously applied if the content of the file changed (either according to size or mtime), but was not being copied back for a mode-only change. That would seem to indicate handling this in an 'elif' branch, but I opted not to in order to avoid copying back the mode without the content changes when mtime and size are unchanged. (Yes, that's a rare corner case, but all the more reason not to have a subtle difference in behavior.) The only way I can think to handle this undetected change is to set each file in the non-wdir() snapshot to readonly, and check for that attribute (as well as mtime) when deciding to copy back. That would avoid the overhead of copying the whole file when only the mode changed. But a chmod in a diff tool is likely rare. See also affd753ddaf1.

tests: remove regular expression matching for Python 2.6 This effectively reverts 52cca17ac523. Some lines still have (re) due to variable length port numbers. There's not much we can do about that. But at least this change removes most of the ugliness.

branchmap: remove use of buffer() to support Python 2.6 The use of buffer() was added in 7359157b9e46 to support Python 2.6, which we no longer support.

py3: remove delayed import of importlib All supported versions of Python now have importlib. This effectively reverts b85fa6bf298b.

tests: use context manager form of assertRaises Support for using unittest.TestCase.assertRaises as a context manager was added in Python 2.7. This form is more readable, especially for complex tests. While I was here, I also restored the use of assertRaisesRegexp, which was removed in c6921568cd20 for Python 2.6 compatibility.

obsolete: use 2 argument form of enumerate() The 2 argument form of enumerate was added in Python 2.6. This change effectively reverts 10880c8aad85.

tests: remove special handling for undefined memoryview 'memoryview' was introduced in Python 2.7. 4adc090fa2fb added code to filterpyflakes.py to ignore "undefined name 'memoryview'" pyflakes warnings. Since we no longer support <Python 2.7, we can remove this workaround.

encoding: remove workaround for locale.getpreferredencoding() locale.getpreferredencoding() was buggy in OS X for Python <2.7. Since we no longer support Python <2.7, we no longer need this workaround. This essentially reverts 2be70ca17311.

mail: remove code to support < Python 2.7 This code was added in 594b98846ce1. Since we no longer support Python <2.7, it can be removed.

help: clarify that colons are allowed in fingerprints values This was suggested by Lars Rohwedder in issue5559.

sslutil: tweak the legacy [hostfingerprints] warning message Lars Rohwedder noted in issue5559 that the previous wording was confusing. I agree.

rebase: allow rebase even if some revisions need no rebase (BC) (issue5422) This allows you to do e.g. "hg rebase -d @ -r 'draft()'" even if some drafts are already based off of @. You'd still need to exclude obsolete and troubled revisions, though. We will deal with those cases later. Implemented by treating state[rev]==rev as "no need to rebase". I considered adding another fake revision number like revdone=-6. That would make the code clearer in a few places, but would add extra code in other places. I moved the existing test out of test-rebase-base.t and into a new file and added more tests there, since not all are using --base.

chgserver: more explicit about sensitive environ variables Environment variables like HGUSER, HGEDITOR, HGEDITFROM should not trigger a new chgserver. This patch uses a whitelist for environ variables starting with "HG" to reduce the number of servers. I have went through `grep -o "[\"']HG[A-Z_0-9]*['\"]" -hR . | sort -u` so the list should be up-to-date.

scmutil: make simplekeyvaluefile able to have a non-key-value first line To ease migration from files with version numbers in their first lines, we want simplekeyvaluefile to support a non-key-value first line. In this way, old versions of Mercurial will read such files, discover a newer version than the one they know how to handle and fail gracefully, rather than with exception. Shelve's shelvestate file is an example.

scmutil: add simplekeyvaluefile reading test Before this patch, mockvfs did not emulate readlines correctly and there was no test for simplekeyvaluefile reading.

caches: stop warming the cache after changegroup application Now that we garantee that branchmap cache is updated at the end of the transaction we can drop this update. This removes a problematic case with nested transaction where the new cache could be written on disk before the transaction is finished (and even roll-backed) Such premature cache write was visible in the following test: * tests/test-acl.t * tests/test-rebase-conflicts.t In addition, running the cache update later means having more date about the state of the repository (in particular: phases). So we can generate caches with more information. This creates harmless changes to the following tests: * tests/test-hardlinks-whitelisted.t * tests/test-hardlinks.t * tests/test-phases.t * tests/test-tags.t * tests/test-inherit-mode.t

caches: move the 'updating the branch cache' message in 'updatecaches' We are about to remove the branchmap cache update in changegroup application. There is a debug message alongside this update that we do not want to loose. We move the message beforehand to simplify the test update in the next changeset. The message move is quite noisy and isolating that noise is useful. Most tests update are just line reordering since the message is issued at a later point during the transaction. After this changes, the message is displayed in more case since local commit creation also issue it.

caches: stop warming the cache after 'localrepo.commitctx' Now that we garantee that branchmap cache are updated at the end of the transaction we can drop that one. This removes a problematic case with nested transaction where the new cache could be written on disk before the transaction is finished. The test change is harmless, since we update the cache at a later point, the dirstate have been updated in between.

caches: introduce a 'debugupdatecaches' command That command make sure caches are updated. This is based on 'localrepo.updatecaches' so when we move support for new cache in that function this command will benefit from it.

caches: call 'repo.updatecache()' in 'repo.destroyed()' Regenerating the cache after a 'strip' or a 'rollback' is useful. So we call the generic cache warming function as other caches than just branchmap will be updated there in the future. To do so, we have to make 'repo.updatecache()' able to take no arguments. In such cases, we reload all caches.

caches: introduce a function to warm cache We have multiple caches that gain from being kept up to date. For example in a server setup, we want to make sure the branchcache cache is hot for other read-only clients. Right now each cache tries to update themself in place where new data have been added. However the approach is error prone (we might miss some spot) and fragile. When nested transaction are involved, such cache updates might happen before a top level transaction is committed. Writing caches for uncommitted data on disk. Having a single entry point, run at the end of each successful transaction, helps to ensure the cache is up to date and refreshed at the right time. We start with updating the branchmap cache but other will come.

transaction: track newly introduced revisions Tracking revisions is not the data that will unlock the most new capability. However, they are the simplest thing to track and still unlock some nice improvements in regard with caching. We plug ourself at the changelog level to make sure we do not miss any revision additions. The 'revs' set is configured at the repository level because the transaction itself does not needs to know that much about the business logic.

transaction: introduce "changes" dictionary to precisely track updates The transaction is already tracking some data intended for hooks (in 'hookargs'). However, that information is minimal as we optimise for passing data to other processes through environment variables. There are multiple places were we could use more complete and lower level information locally (eg: cache update, better report of changes to hooks, etc...). For this purpose we introduces a 'changes' dictionary on the transaction. It is intended to track every changes happening to the repository (eg: new revs, bookmarks move, phases move, obs-markers, etc). For now we just adds the 'changes' dictionary. We'll adds more tracking and usages over time.

clone: add a server-side option to disable full getbundles (pull-based clones) For large enough repositories, pull-based clones take too long, and an attempt to use them indicates some sort of configuration or other issue or maybe an outdated Mercurial. Add a config option to disable them.

clone: warn when streaming was requested but couldn't be performed This helps both users and the people who support them figure out why a stream clone couldn't be performed. In an upcoming patch we're going to add a way for servers to hard abort on a full getbundle. In those cases servers might expect clients to perform a stream clone, so it's important to communicate why one couldn't be done.

clone: test streaming disabled because client is missing requirement Turns out we had no coverage for this important case.

bundle2: don't check for whether we can do stream clones At the moment this isn't used and all stream clones use the legacy protocol. In an upcoming diff, canperformstreamclone will print out a message if a stream clone was requested but couldn't happen for some reason. Removing this call ensures the message isn't printed twice.

debugcommands: add debugpickmergetool to examine which merge tool is chosen Before this patch, there is no convenient way to know which merge tool is chosen for each managed files without actual merging.

filemerge: add internal merge tool to dump files forcibly Internal merge tool :dump implies premerge. Therefore, files aren't dumped, if premerge runs successfully. This undocumented behavior might confuse users, if they want to always dump files. But just making :dump omit premerge might cause backward compatibility issue for existing automation. This patch adds new internal merge tool :forcedump, which works as same as :dump, but omits premerge always. Internal tools annotated with "nomerge" should merge "change and delete" correctly, but _forcedump() can't. Therefore, it is annotated with "mergeonly" to always omit premerge, even though it doesn't merge files actually. This patch also adds explanation about premerge to :dump, to clarify how :dump actually works. BTW, this patch specifies internal tools with "internal:" prefix in newly added test scenario in test-merge-tools.t, even though this prefix is already deprecated. This is only for similarity to other tests in test-merge-tools.t.

filemerge: make warning message more i18n friendly Before this patch, " specified for " part of warning messages (e.g. "couldn't find merge tool TOOL specified for PAT") isn't translatable.

filemerge: show warning about choice of :prompt only at an actual fallback Before this patch, internal merge tool :prompt shows "no tool found to merge FILE" line, even if :prompt is explicitly specified as a tool to be used. This patch shows warning message about choice of :prompt only at an actual fallback, in which case any tool is rejected by capability for binary or symlink. It is for backward compatibility to omit warning message in "changedelete" case.

treemanifest: allow manifestrevlog to take an explicit treemanifest arg Previously we relied on the opener options to tell the revlog to be a tree manifest. This makes it complicated for extensions to create treemanifests and normal manifests at the same time. Let's add a construtor argument to create a treemanifest revlog as well. I considered removing the options['treemanifest'] logic from manifestrevlog entirely, but doing so shifts the responsibility to the caller which ends up requiring changes in localrepo, bundlerepo, and unionrepo. I figured having the dual mechanism was better than polluting other parts of the code base with treemanifest knowledge.

policy: relax the default for in-place build We're going to make the 'c' policy more strict, where no missing attribute will be allowed. Since we want to run 'hg bisect' without rebuilding the C extension modules, we'll need a looser policy for development environment. The default for system installation isn't changed. Note that the current 'c' policy is practically 'allow'-ish as we have lots of adhoc fallbacks to pure functions.

verify: always check rawsize Previously, verify only checks "rawsize == len(rawtext)", if "len(fl.read()) != fl.size()". With flag processor, "len(fl.read()) != fl.size()" does not necessarily mean "rawsize == len(rawtext)". So we may miss a useful check. This patch removes the "if len(fl.read()) != fl.size()" condition so the rawsize check is always performed. With the condition removed, "fl.read(n)" looks unnecessary so a comment was added to explain the side effect is wanted.

rebase: rename "target" to "destination" in messages The help text for rebase calls it "the destination" (never "target"), so let's use that in messages as well.

rebase: rename "target" to "dest" in variable names It took me a while to figure out that "target" was actually what's passed to --dest.

sslutil: remove conditional cipher code needed for Python 2.6 We dropped support for Python 2.6. So this code to work around a missing feature on 2.6 is no longer necessary.

merge: use repo.wvfs.setflags() instead of util.setflags() Most merge.py code goes through the vfs instead of maniulating files directly, so let's do the same here.

merge with stable

revlog: move part of "addrevision" to "addrawrevision" "addrawrevision" will be the public API to reuse revision rawdata elsewhere. It will be used by a future patch.

filectx: add an overlayfilectx class The end goal is to make it possible to avoid potential expensive fctx.data() when unnecessary. While memctx is useful for creating new file contexts, there are many cases where we could reuse an existing raw file revision (amend, histedit, rebase, process a revision constructed by a remote peer, etc). The overlayfilectx class is made to support such reuse cases. Together with a later patch, hash calculation and expensive flag processor could be avoided.

filectx: remove __new__ It does not seem to be used anywhere, and breaks a later patch.

filectx: add a rawflags method The new method returns the low-level revlog flag. We already have "rawdata" so a "rawflags" makes sense. Both "rawflags" and "rawdata" will be used in a later patch.

filectx: move size to basefilectx See previous patch for context - avoid code duplication.

filectx: make renamed a property cache See previous patch for context - mainly to avoid code duplication.

filectx: make flags a property cache Make basefilectx._flags a property cache, so basefilectx.flags() could be reasonably reused. This avoids code duplication between memfilectx and a class added in a later patch.

commandserver: move printbanner logic to bindsocket bindsocket now handles listen automatically. "printbanner" seems to be just a part of "bindsocket". This simplifies the interface a bit.

commandserver: move "listen" responsibility from service to handler This enables chg to replace a server socket in an atomic way: 1. bind to a temp address 2. listen 3. rename Currently 3 happens before 2 so a client may see the socket file but fails to connect to it.

hghave: remove py27+ capability It is now unused. And we require Python 2.7+ now so this check is not necessary.

tests: remove test targeting Python 2.6 We just removed support for Python 2.7. This test is dead since it only ran on <2.7.

setup: drop support for Python 2.6 (BC) Per discussion on the mailing list and elsewhere, we've decided that Python 2.6 is too old to continue supporting. We keep accumulating hacks/fixes/workarounds for 2.6 and this is taking time away from more important work. So with this patch, we officially drop support for Python 2.6 and require Python 2.7 to run Mercurial.

perf: move revlog construction and length calculation out of benchmark We don't need to measure the time it takes to open the revlog or calculate its length. This is more consistent with what other perf* functions do. While I was here, I also renamed the revlog variable from "r" to "rl" - again in the name of consistency.

perf: clear revlog caches on every iteration cmdutil.openrevlog() may return a cached revlog instance. This /may/ be a recent "regression" due to refactoring of the manifest API. I'm not sure. Either way, this perf command was broken for at least manifests because subsequent invocations of the perf function would get cache hits from previous invocations, invalidating results. In the extreme case, testing the last revision in the revlog resulted in near-instantanous execution of subsequent runs (since the fulltext is cached). A time of ~1us would be reported in this case.

perf: don't convert rev to node before calling revlog.revision()

revlog: rename _chunkraw to _getsegmentforrevs() This completes our rename of internal revlog methods to distinguish between low-level raw revlog data "segments" and higher-level, per-revision "chunks." perf.py has been updated to consult both names so it will work against older Mercurial versions.

perf: store reference to revlog._chunkraw in a local variable To prepare for renaming revlog._chunkraw, we stuff a reference to this metho in a local variable. This does 2 things. First, it moves the attribute lookup outside of a loop, which more accurately measures the time of the code being invoked. Second, it allows us to alias to different methods depending on their presence (perf.py needs to support running against old Mercurial versions). Removing an attribute lookup from a tigh loop appears to shift the numbers slightly with mozilla-central: $ hg perfrevlogchunks -c ! read ! wall 0.354789 comb 0.340000 user 0.330000 sys 0.010000 (best of 28) ! wall 0.335932 comb 0.330000 user 0.290000 sys 0.040000 (best of 30) ! read w/ reused fd ! wall 0.342326 comb 0.340000 user 0.320000 sys 0.020000 (best of 29) ! wall 0.332857 comb 0.340000 user 0.290000 sys 0.050000 (best of 30) ! read batch ! wall 0.023623 comb 0.020000 user 0.000000 sys 0.020000 (best of 124) ! wall 0.023666 comb 0.020000 user 0.000000 sys 0.020000 (best of 125) ! read batch w/ reused fd ! wall 0.023828 comb 0.020000 user 0.000000 sys 0.020000 (best of 124) ! wall 0.023556 comb 0.020000 user 0.000000 sys 0.020000 (best of 126)

revlog: rename internal functions containing "chunk" to use "segment" Currently, "chunk" is overloaded in revlog terminology to mean multiple things. One of them refers to a segment of raw data from the revlog. This commit renames various methods only used within revlog.py to have "segment" in their name instead of "chunk." While I was here, I also made the names more descriptive. e.g. "_loadchunk()" becomes "_readsegment()" because it actually does I/O.

fsmonitor: do not nuke dirstate filecache In the future, chg may prefill repo's dirstate filecache so it's valuable and should be kept. Previously we drop both filecache and property cache for dirstate during fsmonitor reposetup, this patch changes it to only drop property cache but keep the filecache.

perf: move gettimer() call This is more consistent with other perf* functions.

perf: don't clobber startrev variable Previously, the "startrev" argument would be ignored due to "startrev = 0" in the benchmark function. This meant that `hg perfrevlog` always started at revision 0. Rename the local variable to "beginrev" so the variable does the right thing.

bundle: add optional 'tagsfnodecache' data to on disk bundle (issue5543) This should help performance when unbundling.

bundle2: move tagsfnodecache generation in a generic function This will help us reusing the logic for `hg bundle`.

bundle: introduce an higher level function to write bundle on disk The current function ('writebundle') is focussing on getting an existing changegroup to disk. It is no easy ways to includes more part in the generated bundle2. So we introduce a slightly higher level function that is fed the 'outgoing' object (that defines the bundled spec) and the bundlespec parameters (to control the changegroup generation and inclusion of other parts). This is creating the third logic dedicated to create a consistent bundle2 (the other 2 are the push code and the getbundle code). We should probably reconcile them at some points but they all takes different types of input. So we need to introduce an intermediate "object" that each different input could be converted to. Such unified "bundle2 specification" could be fed to some unified code. We start by having the `hg bundle` related code on its own to helps defines its specific needs first. Once the common and specific parts of each logic will be known we can start unification.

bundle: handle compression earlier We can also handle that part before starting any generation.

bundle: check changegroup version earlier We can check if we know how to bundle this changegroup version before actually starting to generate the changegroup.

bundle: check lack of revs to bundle before generating the changegroup We already have the information so we can check it earlier.

extdiff: copy back files to the working directory if the size changed In theory, it should be enough to pay attention only to the modification time when detecting if a snapshotted working directory file changed. In practice, BeyondCompare preserves all file attributes when syncing files at the directory level. (If you open the file and sync individual hunks, then mtime does change, and everything was being copied back as desired.) I'm not sure how many other synchronization tools would trigger this issue, but it's annoyingly inconsistent (if a single file is diffed, it isn't snapshotted, so the same BeyondCompare file sync operation _is_ visible, because wdir() is updated in place. I filed a bug with them, and they stated it is on their wish list, but won't be fixed in the near term. This isn't a complete fix (there is still the case of the size not changing), but this seems like a trivial enough change to fix most of the problem. I suppose we could fool around with making files in the other snapshot readonly, and copy back if we see the readonly bit copied. That seems pretty hacky though, and only works if the external tool copies all attributes.

test-extdiff: enable a previously failing test on Windows

test-extdiff: narrow the range of an '#if execbit' block Now that output can be conditionalized, the few `chmod +x` specific outputs can be conditionalized, and the rest of the tests run as normal. Disable one test that is failing on Windows for now.

test-extdiff: deduplicate tests

test-extdiff: fill in a missing Windows test

policy: eliminate ".pure." from module name only if marked as dual So we can switch cext/pure modules to new layout one by one.

policy: add "cext" package which will host CPython extension modules I'm going to restructure cext/pure modules and get rid of our hgimporter hack. C extension modules will be moved to cext/ directory so old and new compiled modules can coexist in development tree. This is necessary to run 'hg bisect' without recompiling. New extension modules will be loaded by an importer function: base85 = policy.importmod('base85') # select pure.base85 or cext.base85 This will also allow us to split cffi from pure modules, which is currently difficult because pure modules can't be imported by name.

policy: mark all string literals as sysstr or bytes The policy module won't be imported early in future, which means string literals will be processed by our Python 3 loader.

debuginstall: check C extensions only if they are loadable per policy This check is useless in pure installation and I want to make it directly import C extension modules.

osutil: proxy through util (and platform) modules (API) See the previous commit for why. Marked as API change since osutil.listdir() seems widely used in third-party extensions. The win32mbcs extension is updated to wrap both util. and windows. aliases.

win32mbcs: wrap underlying pycompat.bytestr to use checkwinfilename safely win32mbcs wraps some functions, to prevent them from unintentionally treating backslash (0x5c), which is used as the second or later byte of multi bytes characters by problematic encodings, as a path component delimiter on Windows platform. This wrapping assumes that wrapped functions can safely accept unicode string arguments. Unfortunately, d1937bdcee8c broke this assumption by introducing pycompat.bytestr() into util.checkwinfilename() for py3 support. After that, wrapped checkwinfilename() always fails for non-ASCII filename at pycompat.bytestr() invocation. This patch wraps underlying pycompat.bytestr() function to use util.checkwinfilename() safely. To avoid similar regression in the future, another patch series will add smoke testing on default branch.

hghave: prefill more version of Mercurial The previous code was unable to go above version 4.0.

graft: fix graft across merges of duplicates of grafted changes Graft used findmissingrevs to find the candidates for graft duplicates in the destination. That function operates with the constraint: 1. N is an ancestor of some node in 'heads' 2. N is not an ancestor of any node in 'common' For our purpose, we do however have to work correctly in cases where the graft set has multiple roots or where merges between graft ranges are skipped. The only changesets we can be sure doesn't have ancestors that are grafts of any changeset in the graftset, are the ones that are common ancestors of *all* changesets in the graftset. We thus need: 2. N is not an ancestor of all nodes in 'common' This change will graft more correctly, but it will also in some cases make graft slower by making it search through a bigger and unnecessary large sets of changes to find duplicates. In the general case of grafting individual or linear sets, we do the same amount of work as before.

graft: test coverage of grafts and how merges can break duplicate detection This demonstrates unfortunate behaviour: extending the graft range cause the graft to behave differently. When the graft range includes a merge, we fail to detect duplicates that are ancestors of the merge.

mpatch: proxy through mdiff module See the previous commit for why.

bdiff: proxy through mdiff module See the previous commit for why. mdiff seems a good place to host bdiff functions. bdiff.bdiff was already aliased as textdiff, so we use it.

base85: proxy through util module I'm going to replace hgimporter with a simpler import function, so we can access to pure/cext modules by name: # util.py base85 = policy.importmod('base85') # select pure.base85 or cext.base85 # cffi/base85.py from ..pure.base85 import * # may re-export pure.base85 functions This means we'll have to use policy.importmod() function in place of the standard import statement, but we wouldn't want to write it every place where C extension modules are used. So this patch makes util host base85 functions.

mdiff: move re-exports to top This style seems more common in our codebase.

test-commit-interactive-curses: remove unused import of parsers

churn: use the non-deprecated template option in the examples

strip: make tree stripping O(changes) instead of O(repo) The old tree stripping logic iterated over every tree revlog in the repo looking for commits that had revs to be stripped. That's very inefficient in large repos. Instead, let's look at what files are touched by the strip and only inspect those revlogs. I don't have actual perf numbers, since internally we don't use a true treemanifest, but simply iterating over hundreds of thousands of revlogs takes many, many seconds, so this should help tremendously when stripping only a few commits.

strip: move tree strip logic to it's own function This will allow external extensions to modify tree strip behavior more precisely.

manifest: remove unused property _oldmanifest The last use seems to have gone away in 7c7d845f8b64 (manifest: make manifestlog use it's own cache, 2016-11-10).

sslutil: reference fingerprints config option properly (issue5559) The config option is "host:fingerprints" not "host.fingerprints". This warning message is bad and misleads users.

py3: convert key to str to make kwargs.pop work in mq The keys are passed here and there as unicodes and our transformer make things bytes. Due to that, mq was not poped and this results in error on Py3. Here we abuse r'' to make that str on Python 3.

py3: convert kwargs' keys to str before passing in cmdutil.getcommiteditor

diff: add a fast path to avoid loading binary contents When diffing binary contents, with certain configs, we can show "Binary file <name> has changed" without actual content. That allows a fast path where we could avoid providing actual binary contents. Note: in that case we still need to test if two contents are the same, that's done by using "filectx.cmp", which could have its own fast path.

diff: correct binary testing logic This seems to be more correct given the table drawn in the previous patch. Namely, "losedatafn" and "opts.git" are removed, "not opts.text" is added. - losedatafn: diff output (binary) should not be affected by "losedatafn" - opts.git: binary testing is helpful for detecting a fast path in the next path. the fast path can also be used if opts.git is False - opts.text: if it's set, we should treat the content as non-binary

diff: draw a table about binary diff behaviors The table should make it easier to reason about future changes.

diff: use fctx.size() to test empty fctx.size() could have a fast path that does not require loading content.

diff: use fctx.isbinary() to test binary The end goal is to avoid calling fctx.data() when unnecessary. For example, if diff.nobinary=1 and files are binary, the expected behavior is to print "Binary file has changed". That could avoid reading fctx.data() sometimes. This is mainly to enable an external LFS extension to skip expensive binary file loading sometimes (read: most of the time with diff.nobinary=1 and diff.text=0), without any behavior changes to mercurial (i.e. whether a file is LFS or not does not change any behavior, LFS could be 100% transparent to users).

pycompat: extract helper to raise exception with traceback It uses "raise excobj, None, tb" form which I think is simpler and more useful than "raise exctype, args, tb".

largefiles: make sure debugstate command is populated before wrapping Copied the hack from 869d660b8669, which seemed the simplest workaround. Perhaps debugcommands.py should have its own commands table.

check-code: ignore re-exports of os.environ in encoding.py These are valid uses of os.environ.

check-code: exclude demandimport.py and policy.py from Python 3 checks These modules can't depend on pycompat.py, which means we have to write Py3 hacks in them.

check-code: rewrite py3 exclusion pattern with negative lookahead I want to add more patterns, but negative lookbehind requires patterns of the same length so not useful.

cleanup: remove useless re-raises of KeyboardInterrupt KeyboardInterrupt is no longer a subclass of Exception since Python 2.5. https://docs.python.org/2/whatsnew/2.5.html#pep-352-exceptions-as-new-style-classes

make: drop deprecated rule to process temporary copy of pure modules Pure modules never be copied to mercurial/ since 511a4384b033.

help: describe about choice of :prompt as a fallback merge tool explicitly "merge-tools" help topic has described that the merge of the file fails if no tool is found to merge binary or symlink, since c77f6276c9e7 (or Mercurial 1.7), which based on (already removed) MergeProgram wiki page. But even at that revision, and of course now, merge of the file doesn't fail automatically for binary/symlink. ":prompt" (or equivalent logic) is used, if there is no appropriate tool configuration for binary/symlink.

wix: only one KeyPath is allowed per Component

dirstate: optimize walk() by using match.visitdir() We already have the logic for restricting directory walks in match.visitdir() that we use for treemanifests. We should take advantage of it when walking the working copy as well. This speeds up "hg st -I rootfilesin:." on the Firefox repo from 0.587s to 0.305s on warm disk (and much more on cold disk). More time is spent reading the dirstate than walking the working copy after. I tried to find scenarios where calling match.visitdir() would be a noticeable overhead, but I couldn't find any. I encourage the reader to try for themselves, since this is performance-critical code.

match: optimize visitdir() for patterns matching only root directory Because _rootsanddirs() returns a list of directories to visit recursively and a list of directories to visit non-recursively. For patterns such as 'rootfilesin:foo/bar', we clearly need to visit the directory foo/bar, but we also need to visit its parents. The method therefore uses util.dirs() to find the parent directories of 'foo/bar'. That method does not include the root directory, but since we obviously need to visit the root directory, we always added '.' to the set of directories to visit non-recursively. The visitdir() method had special handling to consider set(['.']) to mean that no includes had been specified and would thus visit all directories. However, when the pattern is 'rootfilesin:.', set(['.']) is actually the real set of directories to visit and the special handling of that set meant that all directories got visited instead of just the root directory. The fix is simple: add '.' to the set of parent directories in _rootsanddirs() and stop treating set(['.']) specially. This makes hg files -r . -I rootfilesin:. in a treemanifest version of the Firefox repo go from 1.5s to 0.26s on warm disk (and a *much* bigger improvement on cold disk). Note that the -I is necessary for no good reason. We just haven't optimized visitdir() for regular (non-include, non-exclude) patterns yet.

rebase: don't update state dict same way for each root The update statement does not depend on anything in the loop, so just move it before the loop and do it once. There are no cases where update would happen 0 times before (and 1 now); the function returns early in all such cases.

forget: access status fields by name, not index

demandimport: add urwid.command_map to ignore list The useful pudb debugger can be used with Mercurial, but its import of urwid fails when demandimport is enabled. Add urwid.command_map to the ignore list so pudb can be used with hg without disabling all of demandimport.