py3: remove long() compatibility code

zeroconf: constant-fold a `pycompat.ispy3` I’ve checked that both bytes and str gets passed as the `name` parameter, so the rest of the condition is still required. Because there aren’t really any tests for the extensions, I didn’t want to refactor it to pass a single type.

py3: remove conditional to import collections.abc.MutableMapping

py3: remove dead code to open file with O_CLOEXEC on Python 2 The O_CLOEXEC flag is passed by default on Python 3.

py3: don’t encode node.bin() argument It accepts str and bytes.

convert: inline Python 3 variant of url2pathname_like_subversion()

py3: constant-fold some `pycompat.ispy3`

py3: use `zip()` instead of trying to use `itertools.izip()`

py3: replace mention of “xrange” in docstring by “range”

py3: remove xrange() compatibility code Some code used its own xrange() compatibility code instead of pycompat.xrange().

py3: replace `pycompat.xrange` by `range`

hgweb: remove dead code handling UnicodeDecodeError I’m quite confident that the error can’t happen on Python 3, as the main motivation for separating bytes and str in Python 3 was to avoid this class of errors.

cleanup: remove import of already imported module

cleanup: rename some functions to avoid redefinitions

thirdparty: remove Python 2-specific selectors2 copy The selectors module was added in Python 3.4. Because we require Python 3.6, it will always be available. Therefore the selectors2 module is not imported. I’ve verified that the selectors2-specific workaround in commandserver.py is not necessary with the selectors module from the standard library. It returns an empty list if timeout was exceeded. The pytype directive was needed to silence the following error: File "/tmp/mercurial-ci/mercurial/worker.py", line 299, in _posixworker: No attribute 'close' on int [attribute-error] In Union[_typeshed.HasFileno, int] File "/tmp/mercurial-ci/mercurial/worker.py", line 299, in _posixworker: No attribute 'close' on _typeshed.HasFileno [attribute-error] In Union[_typeshed.HasFileno, int]

branching: merge stable into default

docker: avoid /tmp write access issues by fixing permissions

url: raise error if CONNECT request to proxy was unsuccessful The deleted code didn’t work on Python 3. On Python 2 (or Python 3 after adapting it), the function returned in the error case. The subsequent creation of SSL socket fails during handshake with a nonsense error. Instead, the user should get an error of what went wrong. I don’t see how the deleted code would be useful in the error case. The new code is also closer of what the standard library is doing nowadays that it has proxy support (which we don’t use in the moment). In the test, I use port 0 because all the HGPORTs were already taken. In practice, there should not be any server listening on port 0.

revset: fix the doc of "nodefromfile" This should maybe be called "nodesfromfile", but at least the documentation is correct (it was previously a copy past from follow).

chg: replace mercurial.util.recvfds() by simpler pure Python implementation On Python 3, we have socket.socket.recvmsg(). This makes it possible to receive FDs in pure Python code. The new code behaves like the previous implementations, except that it’s more strict about the format of the ancillary data. This works because we know in which format the FDs are passed. Because the code is (and always has been) specific to chg (payload is 1 byte, number of passed FDs is limited) and we now have only one implementation and the code is very short, I decided to stop exposing a function in mercurial.util. Note on terminology: The SCM_RIGHTS mechanism is used to share open file descriptions to another process over a socket. The sending side passes an array of file descriptors and the receiving side receives an array of file descriptors. The file descriptors are different in general on both sides but refer to the same open file descriptions. The two terms are often conflated, even in the official documentation. That’s why I used “FD” above, which could mean both “file descriptor” and “file description”.

py3: don’t subscript socket.error On Python 2, socket.error was subscriptable. On Python 3, socket.error is an alias to OSError and is not subscriptable. The except block passes the exception to self.send_error(). This fails on both Python 2 (if it was executed) and Python 3, as it expects a string. Getting the attribute .strerror works on Python 2 and Python 3, and has the same effect as the previous code on Python 2.

parsers: drop one extra argument to PyErr_Format GCC gave the following warning during `make local`: mercurial/cext/parsers.c: In function 'dirstate_item_from_v1_data': mercurial/cext/parsers.c:413:30: warning: too many arguments for format [-Wformat-extra-args] 413 | "unknown state: `%c` (%d, %d, %d)", state, mode, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To reproduce, you might need to add the -Wformat-extra-args flag, because it isn't present for me when building for the default python3. But I can see this warning while simply building 6.1 with `make PYTHON=python2 clean local`. I don't think this NULL was useful, because other instances of PyErr_Format() don't have any NULLs as the final argument, but keep in mind that I don't know python's C API.

demandimport: eagerly load msvcrt module on PyPy

search-discovery-case: update documentation of a function We return data, it is simpler when we know what these data means.

ci: drop the phabricator refresh step Now that phabricator is no longer in us, we should avoid this useless step to save time and simplify things.

worker: avoid potential partial write of pickled data Previously, the code wrote the pickled data using os.write(). However, os.write() can write less bytes than passed to it. To trigger the problem, the pickled data had to be larger than 2147479552 bytes on my system. Instead, open a file object and pass it to pickle.dump(). This also has the advantage that it doesn’t buffer the whole pickled data in memory. Note that the opened file must be buffered because pickle doesn’t support unbuffered streams because unbuffered streams’ write() method might write less bytes than passed to it (like os.write()) but pickle.dump() relies on that all bytes are written (see https://github.com/python/cpython/issues/93050). The side effect of using a file object and a with statement is that wfd is explicitly closed now while it seems like before it was implicitly closed by process exit.

mr-template: drop the "title and description" I though I would affect the template in the menu itself, however it just a normal piece of text that should not be here.

hghave: make black version regex work with newer versions of black Black commit 117891878e5be4d6b771ae5de299e51b679cea27 (included in black >= 21.11b0) dropped the string "version " from the output of "black --version". To make the regex work with newer black versions, make matching of "version " optional.

debugindex: add a `rank` column

debugindex: add a `sd-chunk-size` column

debugindex: add a `sidedata-offset` column

debugindex: add a `sd-comp-mode` column

debugindex: add a `chunk-size` column

debugindex: add a `data-offset` column

debugindex: add a `comp-mode` column

debugindex: add a `flags` column

debugindex: add a `delta-base` column

debugindex: add a `full-size` column

debugindex: add a `p2-rev` column This will be useful in case of corrupted index.

debugindex: add a `p1-rev` column This will be useful in case of corrupted index.

debugindex: introduce a concept of "verbose-only" column We are about to add a bunch of new column and most of them are probably only relevant to --verbose. We add some more testing of the `--verbose` mode in a sidedata context.

debugindex: move to a flexible column Each column is now declared as a decorated function. This will make it much simpler to add more new column in the future.

debugindex: rename the parent column to mention nodeid We will add new columns with the "revnum" version of the parent. It will be useful in case we need to inspect a corrupted revlog index.

debugindex: align column name on the right It will be simpler to align everything on the same side, and the right seems a better side as it match the value alignment.

debugindex: move the logic into its own module Adding more information will significantly increase the amount of code. So we move the code into its own module before making it more complex.

debugindex: rename to debugindex debug-revlog-index The command dump some content of the revlog index and omit a lot of information. I am going to make it display the missing information. For clarity, we rename the command to explicitly mention revlog.

node: stop converting binascii.Error to TypeError in bin() Changeset f574cc00831a introduced the wrapper, to make bin() behave like on Python 2, where it raised TypeError in many cases. Another previous approach, changing callers to catch binascii.Error in addition to TypeError, was backed out after negative review feedback [1]. However, I think it’s worth reconsidering the approach. Now that we’re on Python 3 only, callers have to catch only binascii.Error instead of both. Catching binascii.Error instead of TypeError has the advantage that it’s less likely to cover a programming error (e.g. passing an int to bin() raises TypeError). Also, raising TypeError never made sense semantically when bin() got an argument of valid type. As a side-effect, this fixed an exception in test-http-bad-server.t. The TODO was outdated: it was not an uncaught ValueError in batch.results() but uncaught TypeError from the now removed wrapper. Now that bin() raises binascii.Error instead of TypeError, it gets converted to a proper error in wirepeer.heads.<locals>.decode() that catches ValueError (superclass of binascii.Error). This is a good example of why this changeset is a good idea. Catching TypeError instead of ValueError there would not make much sense. [1] https://phab.mercurial-scm.org/D2244

revlog: make try block smaller Making try blocks as small as possible is generally a good idea, especially when catching very general errors like TypeError.

revlog: make round-down pattern clearer

rust: relax im-rc dependency to allow minor updates This "15.0.*" requirement came from 0d99778af68a and is now replaced with plain "15.0". AFAICS, it really should allow (but not necessarily require) im-rc 15.1 . Narrow requirement requirements with wildcard in the version is not used in other places.

branching: merge stable into default

Added signature for changeset 6b10151b9621

Added tag 6.1.3 for changeset 6b10151b9621

narrow_widen_acl: enforce narrowacl in narrow_widen (SEC) Reviewer note: this was sent by the author as a simple bugfix, but can be considered a security patch, since it allows users to access things outside of the ACL, hence the (SEC) prefix. However, this affects the `narrow` extention which is still marked as experimental and has relatively few users aside from large companies with their own security layers on top from what we can gather. We feel (Alphare: or at least, I feel) like pinging the packaging list is enough in this case.

chg: ignore already closed fds when cleaning up This should fix this error we see in the CI from time to time: ``` --- /tmp/mercurial-ci/tests/test-chg.t +++ /tmp/mercurial-ci/tests/test-chg.t.err @@ -187,6 +187,26 @@ $ chg bulkwrite --pager=on --color no --config ui.formatted=True paged! 'going to write massive data\n' killed! (?) + Traceback (most recent call last): + File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/commandserver.py", line 509, in _serverequest + sv.cleanup() + File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/chgserver.py", line 382, in cleanup + self._restoreio() + File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/chgserver.py", line 461, in _restoreio + os.close(fd) + OSError: [Errno 9] Bad file descriptor + Traceback (most recent call last): + File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/commandserver.py", line 693, in _acceptnewconnection + self._runworker(conn) + File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/commandserver.py", line 744, in _runworker + prereposetups=[self._reposetup], + File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/commandserver.py", line 509, in _serverequest + sv.cleanup() + File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/chgserver.py", line 382, in cleanup + self._restoreio() + File "/tmp/hgtests._uvojvqb/install/lib/python/mercurial/chgserver.py", line 461, in _restoreio + os.close(fd) + OSError: [Errno 9] Bad file descriptor [255] ```

test-revlog: adds a new root revision with a delta against nullrev We add a revision with null parent but that is not the first revision of the revlog. It make it a different a case that is worthy of testing.

test-revlog: adds a non-root revision with a delta against nullrev Using a revision with non-null parents makes it a different case that is worthy of testing.

test-revlog: update the patch used to test delta againts nullrev We need to be careful to not create invalid delta for changelog. Changelog is special because it does not use any delta in practice and don't use general delta in its format. Using the new patch will help use to test more cases.

tests: remove hg10 requirement from test-check-pylint.t Since pylint does its own directory traversal to find files to check and doesn't use hg locate command, this requirement is not valid. See also a29f071751df.

tests: add hg10 requirement to test-check-module-imports.t This requirement exists to make sure for hg has locate command, which is used in this test file for getting a list of files to check. Since in theory current versions of tests could be run on older hg, it doesn't hurt to mark even this version requirement (as old as it is). See also: a29f071751df.

tests: work around non-thread-safeness of sysconfig.get_config_var()

worker: implement _blockingreader.readinto() (issue6444) The core logic for readinto() was already implemented in read(), so this is mostly extracting that code into its own method. Another fix for issue6444 was committed to the stable branch: 2fe4efaa59af. That is a minimal fix that implements readinto() only on Python versions that require readinto() (3.8.0 and 3.8.1), which is the right approach for the stable branch. However, I think that this changeset has its value. It improves performance in cases when pickle can use readinto(), it reduces code duplication compared to the other patch, and by defining readinto() on all Python versions, it makes behavior more consistent across all Python versions. This changesets reverts the other change.

worker: stop relying on garbage collection to release memoryview On CPython, before resizing the bytearray, all memoryviews referencing it must be released. Before this change, we ensured that all references to them were deleted. On CPython, this was enough to set the reference count to zero, which results in garbage collecting and releasing them. On PyPy, releasing the memoryviews is not necessary because they are implemented differently. If it would be necessary however, ensuring that all references are deleted would not be suffient because PyPy doesn’t use reference counting. By using with statements that take care of releasing the memoryviews, we ensure that the bytearray is resizable without relying on implementation details. So while this doesn’t fix any observable bug, it increases compatiblity with other and future Python implementations.

worker: add docstring to _blockingreader

worker: explain why pickle reading stream has to be unbuffered

bundle: quick fix to ludicrous performance penalty We tried a `hg bundle --base ':(tip^)' --rev 'all()'` on a large repository and it spent 3 minutes on this 2 list comprehensions. This change remove this cost. There are still a lot of low hanging fruits as the command still take 30 seconds. However this is a trivial patch with a massive speedup so I'll just sent it.

deltas: add a debug-delta-find command to analyse delta search See command documentation for details. For some reason, pytype is confused by our usage of None/deltainfo variable, so I had to quiet it.

deltas: add a `debug.revlog.debug-delta` config option enable output This provide a way to enable the code introduced in the previous changeset. This will provide a large amount of output when applying a bundle with details about each delta "computation".

deltas: add code to display information about the result of `finddeltainfo` I have been looking into performance issue around pull and getting more information about the computation and time involved into applying each revision is very useful. There will be various way to use this new output, so I am introducing the code first.

test: update `test-sparse-revlog` output This got changed at some point.

branching: fix wrong merge conflict resolution from 13dfad0f9f7a 13dfad0f9f7a merged stable into default, but accidentally added the _blockingreader class from stable (but deindented) instead of merging the changes from stable (2fe4efaa59af) into the existing _blockingreader class. This resulted in the _blockingreader being there two times.

debugdeltachain: detect a special case where parents are "skipped" See inline comment for details, this is a case where the delta is neither against p1 or p2, Yet it is still a simple delta part of a simple chain. We now display them as `skip1/skip2` instead of `other`.

debugdeltachain: document the possible value for deltatype So that one can understand what is displayed by the command.

debugdeltachain: also display p1/p2 Looking at the parents is a common need when trying to understanding why a delta was chosen, having it readily available helps a lot.

debugdeltachain: glob variance of "test-generaldelta" We mostly care about generaldelta happening, the exact details of storage size variation is not really important so we can glob it instead of having multiple lines for each variances. This will make updating the output of the command simpler.

debugdeltachain: use the symbolic constant to access entry information This is more robust and easier to read

debugdeltachain: distinct between snapshot and "other" diffs Snapshot are expected to be healthy behavior, while "other" is a bit more suspicious. So we distinct between the two to make it easier to inspect repositories.

branching: merge stable into default

workflow: add a default template for Merge Request Introduce a first basic template to try the feature.

run-tests: prevent race-condition when picking a channel Before this, multiple jobs could search the list at the same time and pick the same free channel. We now project this search/assignment with a simple lock.

run-tests: send the test result after freeing the channel Sending the message about the test being "done" signals to the main thread that a new test can be started. Before this changeset, we sent this signal before freeing the channel, there is room for a race condition where a new test would search for a channel before the old test freed the one it used. This is an example of the failure it would produce: https://foss.heptapod.net/mercurial/mercurial-devel/-/jobs/552404

run-tests: also send a message in the Keyboard interrupt case The next patch will do something equivalent, so lets do the change in an independant changeset first in case we need to bisect something in the future.

revlog: use appropriate format char for int ("i" instead of "I") From https://docs.python.org/3.8/c-api/arg.html#numbers : i (int) [int] Convert a Python integer to a plain C int. I (int) [unsigned int] Convert a Python integer to a C unsigned int, without overflow checking.

revlog: use %d to format int instead of %lu (issue6565) The issue says gcc warns that the data types don't match. I couldn't reproduce the warning locally for some reason, but this patch shouldn't break things. Maybe %lu was simply a copy-paste error from 6b1eae313b2f (https://phab.mercurial-scm.org/D10625).

rhg: correctly handle the case where diffs are encoded relative to nullrev returning a valid entry for nullrev fix chain that delta against nullrev.

test-revlog: test a repository that contains a diff against nullrev We are witnessing a crash in the rust code, so we lets make sure this case is tested.

worker: adapt _blockingreader to work around a python3.8.[0-1] bug (issue6444) Python 3.8.0 is the latest I can load on Ubuntu 18.04, and I regularly hit the TypeError because this function is missing. While it can be avoided by disabling worker usage via config option, that's a bit obscure. I'm limiting the function definition to the narrow range of affected pythons because there were other bugs in this area that were worked around, that I don't fully understand. See the bug report for discussions on why the narrow range, and related commits working around other bugs. Differential Revision: https://phab.mercurial-scm.org/D12627

filelog: show the passed argument on error The error now do more than stating what it need. It also state what it got.

manifest: improve error message in case for tree manifest In the case where tree manifest is not enabled but we still receive an sub directory information for the manifest. The error now inform which sub-directory was passed.

doc: use an absolute path in sys.path The idea and rationale is similar to https://phab.mercurial-scm.org/D12599 (landed as 1b6e381521c5). Differential Revision: https://phab.mercurial-scm.org/D12622

check-py3-compat: use an absolute path in sys.path The idea and rationale is similar to https://phab.mercurial-scm.org/D12599 (landed as 1b6e381521c5). Differential Revision: https://phab.mercurial-scm.org/D12621

branchmap: use a context manager when writing the branchmap This is cleaner and safer. The previous code date from long before we had context manager available.

rhg: align the dirstate v2 writing algorithm with python Use the same algorithm of file append as python does, where we do a manual seek instead of relying on O_APPEND. (see the reasons in the inline comment)

test-dirstate: actually test the append code path in dirstate v2 Apparently it's not sufficient to modify a file to force the dirstate write-out, so the append code path was untested. By removing a file instead of changing we're forcing append to happen.

auto-upgrade: skip the operation if the repository cannot be locked This seems like a fine default behavior for now. If some users wants something more aggressive we can make the behavior configurable in the future. Differential Revision: https://phab.mercurial-scm.org/D12619

auto-upgrade: add a test case where the repository is already locked This show the current behavior when the repository to auto-upgrade is already locked. The current behavior is to abort, which is probably not great. Now that we have a proper test, we can think about the behavior we wants in a later tests. Differential Revision: https://phab.mercurial-scm.org/D12618

wait-on-file: properly wait on any files and symlink This make the utility more useful, for example to wait on a lock file. We also add an explicit -L check since the lock are "weird" symlink. Differential Revision: https://phab.mercurial-scm.org/D12617

debuglock: make the command more useful in non-interactive mode The existing prompt mode simply release the lock immediately in non-interactive mode. That is quite useless in the test so now the non-interactive mode simply wait for a signal. Differential Revision: https://phab.mercurial-scm.org/D12616

auto-upgrade: add a test case with no permission to lock the repository This show the current behavior when the repository is unlockable. The current behavior is to abort, which is probably not great. Now that we have a proper test, we can think about the behavior we want in a later changeset. Differential Revision: https://phab.mercurial-scm.org/D12615

auto-upgrade: introduce a way to auto-upgrade to/from dirstate-v2 This is similar to what we introduced for `share-safe`, but apply to the tracked-hint feature. Differential Revision: https://phab.mercurial-scm.org/D12614

auto-upgrade: introduce a way to auto-upgrade to/from tracked-hint This is similar to what we introduced for `share-safe`, but apply to the tracked-hint feature. Differential Revision: https://phab.mercurial-scm.org/D12613

upgrade: split some logic from UpgradeOperation The logic for automatic-upgrade and the upgrade-repo should be able to use the same code. However that code often need an UpgradeOperation object to function. So we start spliting the Operation into a minimal component that we will be able to reuse outside of the "classic" upgrade path. We will put the base-class to use in the next changeset. Differential Revision: https://phab.mercurial-scm.org/D12612

auto-upgrade: introduce a way to auto-upgrade to/from share-safe This is the first "automatic-upgrade" capability. In the following commits, similar features are coming for other "fast to upgrade" formats. This is different from the `safe-mismatch.source-not-safe` and `safe-mismatch.source-safe` configuration that deal with mismatch between a share and its share-source. Here we are dealing with mismatch between a repository configuration and its actual format. We will need further work for cases were the repository cannot be locked. A basic protection is in place to avoid a infinite loop for now, but it will get proper attention in a later changeset. Differential Revision: https://phab.mercurial-scm.org/D12611

rust: make requirements public These can be used by any client crates (including `rhg`), no need to make them private to the crate. Differential Revision: https://phab.mercurial-scm.org/D12610

clone: use better names for temp files Before this commit, the file names are /tmp/tmpn8smvlr8 After this commit, they are more like /tmp/hg-clone-n8smvlr8/00manifest.ndb3qj52v6, which makes it much clearer what these files correspond to. Differential Revision: https://phab.mercurial-scm.org/D12623

tests: make sure .js files stay in ASCII encoding (issue6559) Differential Revision: https://phab.mercurial-scm.org/D12620

ci: have rust-cargo-test inherit from all This help changing configuration for everything at the same time. This was initially the case before being dropped by mistake in 0ddd5e1f5f67.

copies-sdc: mark upgrade action as changelog only We don't need to recompute the other revlog to add the changelog-v2 feature. This simplify upgrade that use copies-sdc (as shown in the tests).

changelog-v2: mark upgrade action as changelog only We don't need to recompute the others revlog to add the changelog-v2 feature. This does not have much effect in practice as the `copies-sdc` upgrade still triggers the other revlogs. This will be fixed in the next changeset.

copies-sdc: no longer suppress the upgrade output To make sure the upgrade simplification we need are taken into account, we need to see more of the output of `debugupgraderepo`. The --quiet flag simplify the output a lot and globing the `preserved` field mean this output should remains stable across (future) unrelated changes.

copies-sdc: no longer use revlogv2 in `test-copies-in-changeset.t` We only need changelog-v2 and its usage is automatically inferred. So we can simplify the test by dropping this. This is important to test future simplification of the update process in the coming changesets.

fix-ci: backed out changeset 308e45f7b455 The chg variant of the CI see a failure on `tests/test-narrow-pull.t`. Bisecting point the failure as starting at this small changeset… Backing it out, restore the CI on default. It was never broken on stable, which is even more puzzling.

branching: merge stable into default

ci: do not trigger phabricator for merge-request The fast the phabricator steps has a `rules` entry makes it selected for the special `merge_requests` pipelines. The other ones behave as default and are not selected tot the mrege_request pipelines. This result in a second pipeline to be created, with only the phabricator pipeline in it. Which usually succeed fast (since there is nothing to do). This is harmful as this create a false sense of "the series is passing" and Gitlab will use this simplistic pipeline for validation. By explicitly preventing the pipeline to be created in the merge-request case, we prevent this situation to happens Note that the job will be dropped (alonside phabricator) in the next two weeks anyway.

branching: merge with stable

amend: stop specifying matcher, get all copies in wctx When we're recreating the commit that we'll be committing, we don't want to filter our copy information based on just the *new* [versions of the] files we're amending. The test has an example of this case, but for clarity, the situation is: ``` $ hg cp src dst && hg commit <do some work> $ hg amend some_unrelated_file.txt $ hg status --copies A dst A some_unrelated_file.txt ``` What *should* happen is that `dst` should remain marked as a copy of `src`, but this did not previously happen. `matcher` here only includes the files that were specified on the commandline, so it only gets the copy information (if any, in this example there's not) for `some_unrelated_file.txt`. When it goes to apply the memctx to actually create the commit, the file copy information is incomplete and loses the information for the files that shouldn't have been affected at all by the amend. Differential Revision: https://phab.mercurial-scm.org/D12625

amend: add test showing poor behavior when copies are involved Differential Revision: https://phab.mercurial-scm.org/D12624

rust-repo: make `Send` by not storing functions in `LazyCell` We (Google) want to use `Repo` in a context where we can store it in `Mutex<Repo>`. However, that currently doesn't work because it's not `Send` because the `LazyCell` initialization functions are not `Send`. It's easy to fix that by passing them to the `get_or_init()` and `get_mut_or_init()` functions. We'll probably also want `Repo` to be `Send` (and even `Sync`) in core later, so this seems like a step in the right direction. Differential Revision: https://phab.mercurial-scm.org/D12582

obsolete: remove two unused constants I'm not sure what these constants were intended for, but they have no users so it's time to say goodbye. Differential Revision: https://phab.mercurial-scm.org/D12609

node: manually implement Debug I got too irritated today with the default Debug implementation of hg::revlog::Node while playing with a new parser. This isn't quite what I wanted, but it wasn't much code and it at least gives you output that's easy to visually compare to a node.hex()ed identifier from the Python side of things. Sadly, this doesn't influence the output in lldb or the VSCode debugger extension that uses lldb under the covers, but it at least means debug prints are a little more useful. Differential Revision: https://phab.mercurial-scm.org/D12608