view tests/test-histedit-non-commute-abort.t @ 30435:b86a448a2965

zstd: vendor python-zstandard 0.5.0

As the commit message for the previous changeset says, we wish
for zstd to be a 1st class citizen in Mercurial. To make that
happen, we need to enable Python to talk to the zstd C API. And
that requires bindings.

This commit vendors a copy of existing Python bindings. Why do we
need to vendor? As the commit message of the previous commit says,
relying on systems in the wild to have the bindings or zstd present
is a losing proposition. By distributing the zstd and bindings with
Mercurial, we significantly increase our chances that zstd will
work. Since zstd will deliver a better end-user experience by
achieving better performance, this benefits our users. Another
reason is that the Python bindings still aren't stable and the
API is somewhat fluid. While Mercurial could be coded to target
multiple versions of the Python bindings, it is safer to bundle
an explicit, known working version.

The added Python bindings are mostly a fully-featured interface
to the zstd C API. They allow one-shot operations, streaming,
reading and writing from objects implements the file object
protocol, dictionary compression, control over low-level compression
parameters, and more. The Python bindings work on Python 2.6,
2.7, and 3.3+ and have been tested on Linux and Windows. There are
CFFI bindings, but they are lacking compared to the C extension.
Upstream work will be needed before we can support zstd with PyPy.
But it will be possible.

The files added in this commit come from Git commit
e637c1b214d5f869cf8116c550dcae23ec13b677 from
https://github.com/indygreg/python-zstandard and are added without
modifications. Some files from the upstream repository have been
omitted, namely files related to continuous integration.

In the spirit of full disclosure, I'm the maintainer of the
"python-zstandard" project and have authored 100% of the code
added in this commit. Unfortunately, the Python bindings have
not been formally code reviewed by anyone. While I've tested
much of the code thoroughly (I even have tests that fuzz APIs),
there's a good chance there are bugs, memory leaks, not well
thought out APIs, etc. If someone wants to review the code and
send feedback to the GitHub project, it would be greatly
appreciated.

Despite my involvement with both projects, my opinions of code
style differ from Mercurial's. The code in this commit introduces
numerous code style violations in Mercurial's linters. So, the code
is excluded from most lints. However, some violations I agree with.
These have been added to the known violations ignore list for now.

  $ . "$TESTDIR/histedit-helpers.sh"

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > histedit=
  > EOF

  $ initrepo ()
  > {
  >     hg init r
  >     cd r
  >     for x in a b c d e f ; do
  >         echo $x > $x
  >         hg add $x
  >         hg ci -m $x
  >     done
  >     echo a >> e
  >     hg ci -m 'does not commute with e'
  >     cd ..
  > }

  $ initrepo
  $ cd r

log before edit
  $ hg log --graph
  @  changeset:   6:bfa474341cc9
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     does not commute with e
  |
  o  changeset:   5:652413bf663e
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     f
  |
  o  changeset:   4:e860deea161a
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     e
  |
  o  changeset:   3:055a42cdd887
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     d
  |
  o  changeset:   2:177f92b77385
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     c
  |
  o  changeset:   1:d2ae7f538514
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     b
  |
  o  changeset:   0:cb9a9f314b8b
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  

edit the history
  $ hg histedit 177f92b77385 --commands - 2>&1 <<EOF | fixbundle
  > pick 177f92b77385 c
  > pick 055a42cdd887 d
  > pick bfa474341cc9 does not commute with e
  > pick e860deea161a e
  > pick 652413bf663e f
  > EOF
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (pick e860deea161a)
  (hg histedit --continue to resume)

insert unsupported advisory merge record
  $ hg --config extensions.fakemergerecord=$TESTDIR/fakemergerecord.py fakemergerecord -x
  $ hg debugmergestate
  * version 2 records
  local: 8f7551c7e4a2f2efe0bc8c741baf7f227d65d758
  other: e860deea161a2f77de56603b340ebbb4536308ae
  labels:
    local: local
    other: histedit
  unrecognized entry: x	advisory record
  file extras: e (ancestorlinknode = 0000000000000000000000000000000000000000)
  file: e (record type "F", state "u", hash 58e6b3a414a1e090dfc6029add0f3555ccba127f)
    local path: e (flags "")
    ancestor path: e (node null)
    other path: e (node 6b67ccefd5ce6de77e7ead4f5292843a0255329f)
  $ hg resolve -l
  U e

insert unsupported mandatory merge record
  $ hg --config extensions.fakemergerecord=$TESTDIR/fakemergerecord.py fakemergerecord -X
  $ hg debugmergestate
  * version 2 records
  local: 8f7551c7e4a2f2efe0bc8c741baf7f227d65d758
  other: e860deea161a2f77de56603b340ebbb4536308ae
  labels:
    local: local
    other: histedit
  file extras: e (ancestorlinknode = 0000000000000000000000000000000000000000)
  file: e (record type "F", state "u", hash 58e6b3a414a1e090dfc6029add0f3555ccba127f)
    local path: e (flags "")
    ancestor path: e (node null)
    other path: e (node 6b67ccefd5ce6de77e7ead4f5292843a0255329f)
  unrecognized entry: X	mandatory record
  $ hg resolve -l
  abort: unsupported merge state records: X
  (see https://mercurial-scm.org/wiki/MergeStateRecords for more information)
  [255]
  $ hg resolve -ma
  abort: unsupported merge state records: X
  (see https://mercurial-scm.org/wiki/MergeStateRecords for more information)
  [255]

abort the edit (should clear out merge state)
  $ hg histedit --abort 2>&1 | fixbundle
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg debugmergestate
  no merge state found

log after abort
  $ hg resolve -l
  $ hg log --graph
  @  changeset:   6:bfa474341cc9
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     does not commute with e
  |
  o  changeset:   5:652413bf663e
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     f
  |
  o  changeset:   4:e860deea161a
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     e
  |
  o  changeset:   3:055a42cdd887
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     d
  |
  o  changeset:   2:177f92b77385
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     c
  |
  o  changeset:   1:d2ae7f538514
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     b
  |
  o  changeset:   0:cb9a9f314b8b
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  

  $ cd ..