bookmark: deprecate 'bmstore.write' method This function does not collaborate with the transaction and must disappear. As we have likely a lot of third party users, we make it deprecated to let them some time to upgrade their code. Thanks goes to Laurent Charignon for cleanup the last remains of the 'write' method.

ui: add a 'deprecwarn' helper to issue deprecation warnings As discussed on the list, we are adding an official way to keep old API around for a short time in order to help third party developer to catch up. The deprecated API will issue developer warning (issued by default during test runs) to warn extensions authors that they need to upgrade their code without instantaneously breaking tool chains and normal users. The version is passed as an explicit argument so that developer think about it and a potential future script can automatically check for it. This is not build as a decorator because accessing the 'ui' instance will likely be different each time. The message is also free form because deprecated API are replaced in a variety of ways. I'm not super happy about the final rendering of that message, but this is a developer oriented warning and I would like to move forward.

ui: add a 'stacklevel' argument to 'develwarn' This allows helper functions (like deprecation warning) to prepare a devel warning for higher up in the stack. The argument is named after the one in the Python's 'warning,warn' function.

import-checker: tell which symbol causes "direct symbol import" This would be sometimes useful to understand why import-checker.py complains about it.

import-checker: allow absolute imports of sub modules from local packages Before this patch, import-checker.py didn't know if a name in ImportFrom statement are module or not. Therefore, it complained the following example did "direct symbol import from mercurial". # hgext/foo.py from mercurial import hg This patch reuses the dict of local modules to filter out sub-module names.

manifest: use 't' for tree manifest flag We currently use 'd' to indicate that a manifest entry is a directory. Let's switch to 't', since that's not a valid hex digit and therefore easier to spot in the raw manifest data. This will break any existing repos with tree manifests, but it's still an experimental feature and there are probably only a few test repos in existence with 'd' flags.

test: update the docstring of 'test-devel-warnings.t' extension We are testing more than just locks now.

setup.py: don't rewrite @LIBDIR@ when creating wheels This is necessary to produce wheels that install properly. More details are captured in an in-line comment. After this patch, produced wheels can be installed via `pip install` and appear to "just work," including on Windows.

setup.py: attempt to build and install hg.exe on Windows Currently, packaging Mercurial on Windows will produce a Scripts\hg Python script and a Scripts\hg.bat batch script. The py2exe distribution contains a hg.exe which loads a Python interpretter and invokes the "hg" Python script. Running a exe directly has benefits over batch scripts because batch scripts do things like muck around with command arguments. This patch implements a custom "build_scripts" command which attempts to build hg.exe on Windows. If hg.exe is built, it is marked as a "script" file and installed into the Scripts\ directory on Windows. Since hg.exe is redundant and better than hg.bat, if hg.exe is built, hg.bat is not installed. Since some environments don't support compiling C programs, we treat hg.exe as optional and catch failures building it. This is not ideal. However, I reckon most Windows users will not be installing Mercurial from source: they will get it from the MSI installer or via `pip install Mercurial`, which will download a wheel that has hg.exe in it. So, I don't think this is a big deal.

merge.graft: add option to keep second parent Currently merge.graft re-writes the dirstate so only a single parent is kept. For some cases, like evolving a merge commit, this behaviour is not desired. More specifically, this is needed to fix issue4389.

ui: support declaring path push urls as sub-options Power users often want to apply per-path configuration options. For example, they may want to declare an alternate URL for push operations or declare a revset of revisions to push when `hg push` is used (as opposed to attempting to push all revisions by default). This patch establishes the use of sub-options (config options with ":" in the name) to declare additional behavior for paths. New sub-options are declared by using the new ``@ui.pathsuboption`` decorator. This decorator serves multiple purposes: * Declaring which sub-options are registered * Declaring how a sub-option maps to an attribute on ``path`` instances (this is needed to `hg paths` can render sub-options and values properly) * Validation and normalization of config options to attribute values * Allows extensions to declare new sub-options without monkeypatching * Allows extensions to overwrite built-in behavior for sub-option handling As convenient as the new option registration decorator is, extensions (and even core functionality) may still need an additional hook point to perform finalization of path instances. For example, they may wish to validate that multiple options/attributes aren't conflicting with each other. This hook point could be added later, if needed. To prove this new functionality works, we implement the "pushurl" path sub-option. This option declares the URL that `hg push` should use by default. We require that "pushurl" is an actual URL. This requirement might be controversial and could be dropped if there is opposition. However, objectors should read the complicated code in ui.path.__init__ and commands.push for resolving non-URL values before making a judgement. We also don't allow #fragment in the URLs. I intend to introduce a ":pushrev" (or similar) option to define a revset to control which revisions are pushed when "-r <rev>" isn't passed into `hg push`. This is much more powerful than #fragment and I don't think #fragment is useful enough to continue supporting. The [paths] section of the "config" help page has been updated significantly. `hg paths` has been taught to display path sub-options. The docs mention that "default-push" is now deprecated. However, there are several references to it that need to be cleaned up. A large part of this is converting more consumers to the new paths API. This will happen naturally as more path sub-options are added and more and more components need to access them.

ui: pass ui instance to path.__init__ It will be used in a subsequent patch.

ui: store pushloc as separate attribute The magic @property is going to interfere with the ability to print path sub-options. We only access it in one location and it is trivial to in-line, so do that.

commands: add debugdeltachain command We have debug commands for displaying overall revlog statistics (debugrevlog) and for dumping a revlog index (debugindex). As part of investigating various aspects of revlog behavior and performance, I found it important to have an understanding of how revlog delta chains behave in practice. This patch implements a "debugdeltachain" command. For each revision in a revlog, it dumps information about the delta chain. Which delta chain it is part of, length of the delta chain, distance since base revision, info about base revision, size of the delta chain, etc. The generic formatting facility is used, which means we can templatize output and get machine readable output like JSON. This command has already uncovered some weird history in mozilla-central I didn't know about. So I think it's valuable.

histedit: pick an appropriate base changeset by default (BC) Previously, `hg histedit` required a revision argument specifying which revision to use as the base for the current histedit operation. There was an undocumented and experimental "histedit.defaultrev" option that supported defining a single revision to be used if no argument is passed. Mercurial knows what changesets can be edited. And in most scenarios, people want to edit this history of everything on the current head that is rewritable. Making histedit do this by default and not require an explicit argument or additional configuration is a major usability win and will enable more people to use histedit. This patch changes the behavior of the experimental and undocumented "histedit.defaultrev" config option to select an appropriate base revision by default. Comprehensive tests exercising the edge cases in the new, somewhat complicated default revset have been added. Surprisingly, no tests broke. I guess we were never testing the behavior with no ANCESTOR argument (it used to fail with "abort: histedit requires exactly one ancestor revision"). The new behavior is much more user friendly. The functionality for choosing the default base revision has been moved to destutil.py, where it can easily be modified by extensions.