sshpeer: establish SSH connection before class instantiation We want to move the handshake to before peers are created so we can instantiate a different peer class depending on the results of the handshake. This necessitates moving the SSH process invocation to outside the peer class. As part of the code move, some variables were renamed for clarity. util.popen4() returns stdin, stdout, and stderr in their typical file descriptor order. However, stdin and stdout were being mapped to "pipeo" and "pipei" respectively. "o" for "stdin" and "i" for "stdout" is a bit confusing. Although it does make sense for "output" and "input" from the perspective of the client. But in the context of the new function, it makes sense to refer to these as their file descriptor names. In addition, the last use of self._path disappeared, so we stop setting that attribute and we can delete the redundant URL parsing necessary to set it. Differential Revision: https://phab.mercurial-scm.org/D2031

sshpeer: remove frivolous call to _cleanup() _validaterepo() is called once during __init__. _cleanup() no-ops if the self._pipe* attributes aren't set. These attributes are set during _validaterepo(). So the call to _cleanup() isn't necessary. But just to be on the safe side, we add an assertion. Differential Revision: https://phab.mercurial-scm.org/D2030

sshpeer: extract pipe cleanup logic to own function So it can be used outside of instantiated classes. This is needed to support pipe creation before __init__ is called. Differential Revision: https://phab.mercurial-scm.org/D2029

sshpeer: move ssh command and repo creation logic out of __init__ It was easier to move both of these at once because repository creation requires various variables and I didn't want to add tons of arguments and code to __init__ that will soon be deleted anyway. We do add an extra argument so we can proxy values to the _validaterepo() call. But this is minimally invasive. Some callers of self._abort() were converted to just raise. Like before, the _abort() call wasn't necessary because self._pipe* aren't populated this early in the object's lifetime. As part of this, various private attributes derived from the parsed URL are no longer used. So we no longer set them. Differential Revision: https://phab.mercurial-scm.org/D2028

sshpeer: move URL validation out of sshpeer.__init__ We will soon have another SSH peer class to support the new version of the SSH protocol. However, we won't know which peer class to instantiate until we perform a handshake on an active connection. This means that we need to move connection establishment and handshake code out of sshpeer.__init__. This commit starts the process of migrating peer creation code out of sshpeer.__init__ into instance(), which is the API for creating peers. The moved code no longer calls _abort(). _abort() runs _cleanup() and raises. _cleanup() only performs actions on self._pipe*. These objects aren't instantiated until we actually connect to the peer. So _abort() was not necessary in the old code. To keep the API the same, __init__() now makes a redundant call to util.url(). This will be fixed in subsequent commits. Differential Revision: https://phab.mercurial-scm.org/D2027

tests: add low-level SSH protocol tests We don't really have good low-level tests for the behavior of the SSH wire protocol. This commit attempts to establish some. The added tests consist of a mixture of starting a server with `hg serve --stdio` and sending bytes to it and using `hg debugpeer` to go through the official client code. Having insight into what raw bytes are exchanged as well as what the peer does is useful. We also introduce a test extension for modifying the behavior of the SSH server and peer. For example, we change the server to not recognize the "hello" command, simulating behavior of <0.9.1 servers. These tests are generally useful to have. But the impetus for creating them now is they will be needed for verifying behavior of old clients and servers when a new SSH protocol is introduced. Differential Revision: https://phab.mercurial-scm.org/D2026 # no-check-commit because of serve_forever()

debugcommands: introduce debugpeer command `hg debugpeer <path>` will establish a connection to a peer repository and print information about it. If you add --debug, it will log low-level protocol request info. This will be useful for upcoming tests around protocol handshaking. Differential Revision: https://phab.mercurial-scm.org/D2025

sshpeer: make "instance" a function The API is that peer modules must provide an "instance" symbol that is callable to return a peer. Making "instance" a function instead of an alias to "sshpeer" makes it easier to monkeypatch the "sshpeer" type. It will also make it possible to turn instance() into a factory function of sorts that returns different types based on connection properties. Differential Revision: https://phab.mercurial-scm.org/D2024

lfs: deduplicate oids in the transfer Apparently, we can't rely on the server to deduplicate for us. Sadly, the pointer object isn't hashable, so it can't be reduced by converting it to a set. In order to be hashable, it needs to be immutable. I had a bunch of code to change it to composition and forward the readonly dict methods to a member dict. But the pointer is updated via __setitem__() when creating the pointer file. So it didn't see worth adding all of that code to the class.

cat: call the storage prefetch hook It's not important to call in the case of a single file, but maybe it's better to do so for consistency.

archive: call the storage prefetch hook

lfs: prefetch lfs blobs during revert The revert command oddly prints out what it will do before requesting the files to be prefetched. But the 'need to transfer' line indicates the blobs are being grouped.

cmdutil: convert _revertprefetch() to a generic stored file hook (API) This will be used by LFS to fetch required files in a group for multiple commands, prior to being accessed. That avoids the one-at-a-time fetch when the filelog wrapper goes to access it, and it is missing locally (which costs two round trips to the server.) The core command list that needs this is probably at least: - annotate - archive (which is also used by extdiff) - cat - diff - export - grep - verify (sadly) - anything that has the '{data}' template There are no core users of the revert prefetch hook, and never have been since it was introduced in 45e02cfad4bd for remotefilelog. Thanks to Yuya for figuring out a way to reliably trigger the deprecated warning. Unfortunately, it wanted to blame the caller of revert. Passing along an adjusted stack level seemed the least bad choice (although it still blames a core function). One thing to note is that the store lock isn't being held when this is called. I'm not at all familiar with remotefilelog or its locking requirements, so this may not be a big deal. Currently, LFS doesn't hold a lock when downloading files. Even though largefiles doesn't either, I'm starting to think it should, and maybe the .hg/store/lock isn't good enough to cover the globally shared cache. .. api:: The cmdutil._revertprefetch() hook point for prefetching stored files has been replaced by the command agnostic cmdutil._prefetchfiles(). The new function takes a list of files, instead of a list of lists of files.

lfs: prefetch lfs blobs when applying merge updates In addition to merge, this method ultimately gets called by many commands: - backout - bisect - clone - fetch - graft - import (without --bypass) - pull -u - rebase - strip - share - transplant - unbundle - update Additionally, it's also called by histedit, shelve, unshelve, and split, but it seems that the related blobs should always be available locally for these. For `hg update`, it happens after the normal argument checking and pre-update hook processing, and remote corruption is detected prior to manipulating the working directory. Other commands could use this treatment (archive, cat, revert, etc), but this covers so many of the frequently used bulk commands, it seems like a good starting point. Losing the verbose message that prints the file name before a corrupt blob aborts the command is a little sad, because there's no easy way to go from oid to file name. I'd like to change that message to list the file name so it looks cleaner and less cryptic, but the pointer object is nowhere near where it needs to be to do this. So punt on that for now.

lfs: factor out a method for extracting the pointer of a single file This will be useful for filesets, among other things, instead of traversing the whole context.

py3: add b'' to literals in check-config.py # skip-blame because we are just adding b'' Differential Revision: https://phab.mercurial-scm.org/D2046

check-config: specify the mode 'rb' to open the file Differential Revision: https://phab.mercurial-scm.org/D2045

py3: use open() instead of file() file() is not present in Python 3 Differential Revision: https://phab.mercurial-scm.org/D2044

py3: use pycompat.strkwargs() to convert kwargs' key to str Differential Revision: https://phab.mercurial-scm.org/D2043

py3: add __bytes__() for mq.patchheader and make sure __str__ returns str Before this patch, __str__() function for mq.patchheader class return bytes which is not str on Python 3. So let's move that logic to __bytes__() and for __str__() convert the return value of __bytes__() to str. Differential Revision: https://phab.mercurial-scm.org/D2042

py3: use "%d" to convert integer to bytes Differential Revision: https://phab.mercurial-scm.org/D2041

py3: use .startswith() instead of bytes[0] Differential Revision: https://phab.mercurial-scm.org/D2040

py3: slice on bytes to prevent getting the ascii values Differential Revision: https://phab.mercurial-scm.org/D2039

py3: add r'' to convert keys to keyword arguments to str # skip-blame as we are just adding r'' Differential Revision: https://phab.mercurial-scm.org/D2038

py3: add b'' to tweakdefaults config string The tweakdefaults config string is enclosed inside triple quotes and the transformer does not adds b'' there. # skip-blame because we are just adding b'' Differential Revision: https://phab.mercurial-scm.org/D2037

cmdutil: introduce deprecated aliases c8e2d6ed1f9e moved some objects used by Evolve and hence broke the latest Evolve revision. Next Evolve version will use the new objects when available but introduce deprecated aliases so users using older version of Evolve won't have a broken Evolve extension. Differential Revision: https://phab.mercurial-scm.org/D2023

makefile: remove Ubuntu Yakkety and Zesty docker targets Yakkety (16.10) was supported until 2017-07-20 and Zesty (17.04) was supported until 2018-01-13.

merge: use operation-provided labels (ex: dest/source) in several merge-tools Tools that did not use labels already, used only one, or used some label other than the exact strings of "local" or "other" were unmodified. Cases that used the label "base" were modified as well, if they were otherwise changed in this CL; "merged" was *not* changed. There are other possible changes we might want to make, but I didn't: - bcompare (linux and osx) uses the labels "parent1" and "parent2" instead of "local" and "other", so it was left alone, even though beyondcompare3 (windows) *was* changed. - araxis used the labels "Other", "Base", and "Local :$local", so it was also left alone. - UltraCompare didn't provide a label for 'local', just for 'base' and 'other', so it was left alone. Differential Revision: https://phab.mercurial-scm.org/D2012

filemerge: support passing labels to external merge tools This adds $labellocal, $labelother, and $labelbase to the replacement set for merge-tools.<tool>.args config variables, and to the environment as HG_MY_LABEL, HG_OTHER_LABEL, and HG_BASE_LABEL, respectively. We also add merge-tools.<tool>.mergemarkers and merge-tools.<tool>.mergemarkertemplate config variables as counterparts of the variables available in [ui]. We are intentionally *not* respecting ui.mergemarkers when calling out to external merge programs; too often the default template will be too wide to display comfortably in most GUIs. Differential Revision: https://phab.mercurial-scm.org/D2011

bookmarks: drop deprecated methods (API) The ProgrammingError prevents accidental usage of the dict base class methods. .. api:: The following deprecated methods have been removed from bookmarks: __setitem__(), __delitem__(), update(), and recordchange(). Use bookmarks.applychanges() instead.