view tests/test-merge-types.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.

#require symlink execbit

  $ tellmeabout() {
  > if [ -h $1 ]; then
  >     echo $1 is a symlink:
  >     $TESTDIR/readlink.py $1
  > elif [ -x $1 ]; then
  >     echo $1 is an executable file with content:
  >     cat $1
  > else
  >     echo $1 is a plain file with content:
  >     cat $1
  > fi
  > }

  $ hg init test1
  $ cd test1

  $ echo a > a
  $ hg ci -Aqmadd
  $ chmod +x a
  $ hg ci -mexecutable

  $ hg up -q 0
  $ rm a
  $ ln -s symlink a
  $ hg ci -msymlink
  created new head

Symlink is local parent, executable is other:

  $ hg merge --debug
    searching for copies back to rev 1
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: c334dc3be0da, local: 521a1e40188f+, remote: 3574f3e69b1c
   preserving a for resolve of a
   a: versions differ -> m (premerge)
  picked tool ':merge' for a (binary False symlink True changedelete False)
  merging a
  my a@521a1e40188f+ other a@3574f3e69b1c ancestor a@c334dc3be0da
  warning: internal :merge cannot merge symlinks for a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ tellmeabout a
  a is a symlink:
  a -> symlink
  $ hg resolve a --tool internal:other
  (no more unresolved files)
  $ tellmeabout a
  a is an executable file with content:
  a
  $ hg st
  M a
  ? a.orig

Symlink is other parent, executable is local:

  $ hg update -C 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg merge --debug --tool :union
    searching for copies back to rev 1
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: c334dc3be0da, local: 3574f3e69b1c+, remote: 521a1e40188f
   preserving a for resolve of a
   a: versions differ -> m (premerge)
  picked tool ':union' for a (binary False symlink True changedelete False)
  merging a
  my a@3574f3e69b1c+ other a@521a1e40188f ancestor a@c334dc3be0da
  warning: internal :union cannot merge symlinks for a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ tellmeabout a
  a is an executable file with content:
  a

  $ hg update -C 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg merge --debug --tool :merge3
    searching for copies back to rev 1
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: c334dc3be0da, local: 3574f3e69b1c+, remote: 521a1e40188f
   preserving a for resolve of a
   a: versions differ -> m (premerge)
  picked tool ':merge3' for a (binary False symlink True changedelete False)
  merging a
  my a@3574f3e69b1c+ other a@521a1e40188f ancestor a@c334dc3be0da
  warning: internal :merge3 cannot merge symlinks for a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ tellmeabout a
  a is an executable file with content:
  a

  $ hg update -C 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg merge --debug --tool :merge-local
    searching for copies back to rev 1
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: c334dc3be0da, local: 3574f3e69b1c+, remote: 521a1e40188f
   preserving a for resolve of a
   a: versions differ -> m (premerge)
  picked tool ':merge-local' for a (binary False symlink True changedelete False)
  merging a
  my a@3574f3e69b1c+ other a@521a1e40188f ancestor a@c334dc3be0da
  warning: internal :merge-local cannot merge symlinks for a
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ tellmeabout a
  a is an executable file with content:
  a

  $ hg update -C 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg merge --debug --tool :merge-other
    searching for copies back to rev 1
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: c334dc3be0da, local: 3574f3e69b1c+, remote: 521a1e40188f
   preserving a for resolve of a
   a: versions differ -> m (premerge)
  picked tool ':merge-other' for a (binary False symlink True changedelete False)
  merging a
  my a@3574f3e69b1c+ other a@521a1e40188f ancestor a@c334dc3be0da
  warning: internal :merge-other cannot merge symlinks for a
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ tellmeabout a
  a is an executable file with content:
  a

Update to link without local change should get us a symlink (issue3316):

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  1 other heads for branch "default"
  $ hg st
  ? a.orig

Update to link with local change should cause a merge prompt (issue3200):

  $ hg up -Cq 0
  $ echo data > a
  $ HGMERGE= hg up -y --debug
    searching for copies back to rev 2
  resolving manifests
   branchmerge: False, force: False, partial: False
   ancestor: c334dc3be0da, local: c334dc3be0da+, remote: 521a1e40188f
   preserving a for resolve of a
   a: versions differ -> m (premerge)
  (couldn't find merge tool hgmerge|tool hgmerge can't handle symlinks) (re)
  picked tool ':prompt' for a (binary False symlink True changedelete False)
  no tool found to merge a
  keep (l)ocal [working copy], take (o)ther [destination], or leave (u)nresolved? u
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges
  1 other heads for branch "default"
  [1]
  $ hg diff --git
  diff --git a/a b/a
  old mode 120000
  new mode 100644
  --- a/a
  +++ b/a
  @@ -1,1 +1,1 @@
  -symlink
  \ No newline at end of file
  +data


Test only 'l' change - happens rarely, except when recovering from situations
where that was what happened.

  $ hg init test2
  $ cd test2
  $ printf base > f
  $ hg ci -Aqm0
  $ echo file > f
  $ echo content >> f
  $ hg ci -qm1
  $ hg up -qr0
  $ rm f
  $ ln -s base f
  $ hg ci -qm2
  $ hg merge
  merging f
  warning: internal :merge cannot merge symlinks for f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ tellmeabout f
  f is a symlink:
  f -> base

  $ hg up -Cqr1
  $ hg merge
  merging f
  warning: internal :merge cannot merge symlinks for f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ tellmeabout f
  f is a plain file with content:
  file
  content

  $ cd ..

Test removed 'x' flag merged with change to symlink

  $ hg init test3
  $ cd test3
  $ echo f > f
  $ chmod +x f
  $ hg ci -Aqm0
  $ chmod -x f
  $ hg ci -qm1
  $ hg up -qr0
  $ rm f
  $ ln -s dangling f
  $ hg ci -qm2
  $ hg merge
  merging f
  warning: internal :merge cannot merge symlinks for f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ tellmeabout f
  f is a symlink:
  f -> dangling

  $ hg up -Cqr1
  $ hg merge
  merging f
  warning: internal :merge cannot merge symlinks for f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ tellmeabout f
  f is a plain file with content:
  f

Test removed 'x' flag merged with content change - both ways

  $ hg up -Cqr0
  $ echo change > f
  $ hg ci -qm3
  $ hg merge -r1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ tellmeabout f
  f is a plain file with content:
  change

  $ hg up -qCr1
  $ hg merge -r3
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ tellmeabout f
  f is a plain file with content:
  change

  $ cd ..

Test merge with no common ancestor:
a: just different
b: x vs -, different (cannot calculate x, cannot ask merge tool)
c: x vs -, same (cannot calculate x, merge tool is no good)
d: x vs l, different
e: x vs l, same
f: - vs l, different
g: - vs l, same
h: l vs l, different
(where same means the filelog entry is shared and there thus is an ancestor!)

  $ hg init test4
  $ cd test4
  $ echo 0 > 0
  $ hg ci -Aqm0

  $ echo 1 > a
  $ echo 1 > b
  $ chmod +x b
  $ echo 1 > bx
  $ chmod +x bx
  $ echo x > c
  $ chmod +x c
  $ echo 1 > d
  $ chmod +x d
  $ printf x > e
  $ chmod +x e
  $ echo 1 > f
  $ printf x > g
  $ ln -s 1 h
  $ hg ci -qAm1

  $ hg up -qr0
  $ echo 2 > a
  $ echo 2 > b
  $ echo 2 > bx
  $ chmod +x bx
  $ echo x > c
  $ ln -s 2 d
  $ ln -s x e
  $ ln -s 2 f
  $ ln -s x g
  $ ln -s 2 h
  $ hg ci -Aqm2

  $ hg merge
  merging a
  warning: cannot merge flags for b without common ancestor - keeping local flags
  merging b
  merging bx
  warning: cannot merge flags for c without common ancestor - keeping local flags
  merging d
  warning: internal :merge cannot merge symlinks for d
  warning: conflicts while merging d! (edit, then use 'hg resolve --mark')
  merging f
  warning: internal :merge cannot merge symlinks for f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  merging h
  warning: internal :merge cannot merge symlinks for h
  warning: conflicts while merging h! (edit, then use 'hg resolve --mark')
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  warning: conflicts while merging b! (edit, then use 'hg resolve --mark')
  warning: conflicts while merging bx! (edit, then use 'hg resolve --mark')
  3 files updated, 0 files merged, 0 files removed, 6 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ hg resolve -l
  U a
  U b
  U bx
  U d
  U f
  U h
  $ tellmeabout a
  a is a plain file with content:
  <<<<<<< working copy: 0c617753b41b - test: 2
  2
  =======
  1
  >>>>>>> merge rev:    2e60aa20b912  - test: 1
  $ tellmeabout b
  b is a plain file with content:
  <<<<<<< working copy: 0c617753b41b - test: 2
  2
  =======
  1
  >>>>>>> merge rev:    2e60aa20b912  - test: 1
  $ tellmeabout c
  c is a plain file with content:
  x
  $ tellmeabout d
  d is a symlink:
  d -> 2
  $ tellmeabout e
  e is a symlink:
  e -> x
  $ tellmeabout f
  f is a symlink:
  f -> 2
  $ tellmeabout g
  g is a symlink:
  g -> x
  $ tellmeabout h
  h is a symlink:
  h -> 2

  $ hg up -Cqr1
  $ hg merge
  merging a
  warning: cannot merge flags for b without common ancestor - keeping local flags
  merging b
  merging bx
  warning: cannot merge flags for c without common ancestor - keeping local flags
  merging d
  warning: internal :merge cannot merge symlinks for d
  warning: conflicts while merging d! (edit, then use 'hg resolve --mark')
  merging f
  warning: internal :merge cannot merge symlinks for f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  merging h
  warning: internal :merge cannot merge symlinks for h
  warning: conflicts while merging h! (edit, then use 'hg resolve --mark')
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  warning: conflicts while merging b! (edit, then use 'hg resolve --mark')
  warning: conflicts while merging bx! (edit, then use 'hg resolve --mark')
  3 files updated, 0 files merged, 0 files removed, 6 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ tellmeabout a
  a is a plain file with content:
  <<<<<<< working copy: 2e60aa20b912  - test: 1
  1
  =======
  2
  >>>>>>> merge rev:    0c617753b41b - test: 2
  $ tellmeabout b
  b is an executable file with content:
  <<<<<<< working copy: 2e60aa20b912  - test: 1
  1
  =======
  2
  >>>>>>> merge rev:    0c617753b41b - test: 2
  $ tellmeabout c
  c is an executable file with content:
  x
  $ tellmeabout d
  d is an executable file with content:
  1
  $ tellmeabout e
  e is an executable file with content:
  x (no-eol)
  $ tellmeabout f
  f is a plain file with content:
  1
  $ tellmeabout g
  g is a plain file with content:
  x (no-eol)
  $ tellmeabout h
  h is a symlink:
  h -> 1

  $ cd ..