view tests/test-casecollision-merge.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 icasefs

################################
test for branch merging
################################

test for rename awareness of case-folding collision check:

(1) colliding file is one renamed from collided file:
this is also case for issue3370.

  $ hg init branch_merge_renaming
  $ cd branch_merge_renaming

  $ echo a > a
  $ hg add a
  $ echo b > b
  $ hg add b
  $ hg commit -m '#0'
  $ hg tag -l A
  $ hg rename a tmp
  $ hg rename tmp A
  $ hg commit -m '#1'
  $ hg tag -l B
  $ hg update -q 0
  $ touch x
  $ hg add x
  $ hg commit -m '#2'
  created new head
  $ hg tag -l C

  $ hg merge -q
  $ hg status -A
  M A
  R a
  C b
  C x

  $ hg update -q --clean 1
  $ hg merge -q
  $ hg status -A
  M x
  C A
  C b
  $ hg commit -m '(D)'
  $ hg tag -l D

additional test for issue3452:

| this assumes the history below.
|
|  (A) -- (C) -- (E) -------
|      \      \             \
|       \      \             \
|         (B) -- (D) -- (F) -- (G)
|
|   A: add file 'a'
|   B: rename from 'a' to 'A'
|   C: add 'x' (or operation other than modification of 'a')
|   D: merge C into B
|   E: modify 'a'
|   F: modify 'A'
|   G: merge E into F
|
| issue3452 occurs when (B) is recorded before (C)

  $ hg update -q --clean C
  $ echo "modify 'a' at (E)" > a
  $ echo "modify 'b' at (E)" > b
  $ hg commit -m '(E)'
  created new head
  $ hg tag -l E

  $ hg update -q --clean D
  $ echo "modify 'A' at (F)" > A
  $ hg commit -m '(F)'
  $ hg tag -l F

  $ hg merge -q --tool internal:other E
  $ hg status -A
  M A
    a
  M b
  C x
  $ cat A
  modify 'a' at (E)

test also the case that (B) is recorded after (C), to prevent
regression by changes in the future.

to avoid unexpected (successful) behavior by filelog unification,
target file is not 'a'/'A' but 'b'/'B' in this case.

  $ hg update -q --clean A
  $ hg rename b tmp
  $ hg rename tmp B
  $ hg commit -m '(B1)'
  created new head
  $ hg tag -l B1

  $ hg merge -q C
  $ hg status -A
  M x
  C B
  C a
  $ hg commit -m '(D1)'
  $ hg tag -l D1

  $ echo "modify 'B' at (F1)" > B
  $ hg commit -m '(F1)'
  $ hg tag -l F1

  $ hg merge -q --tool internal:other E
  $ hg status -A
  M B
    b
  M a
  C x
  $ cat B
  modify 'b' at (E)

  $ cd ..

(2) colliding file is not related to collided file

  $ hg init branch_merge_collding
  $ cd branch_merge_collding

  $ echo a > a
  $ hg add a
  $ hg commit -m '#0'
  $ hg remove a
  $ hg commit -m '#1'
  $ echo A > A
  $ hg add A
  $ hg commit -m '#2'
  $ hg update --clean 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo x > x
  $ hg add x
  $ hg commit -m '#3'
  created new head
  $ echo 'modified at #4' > a
  $ hg commit -m '#4'

  $ hg merge
  abort: case-folding collision between a and A
  [255]
  $ hg parents --template '{rev}\n'
  4
  $ hg status -A
  C a
  C x
  $ cat a
  modified at #4

  $ hg update --clean 2
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg merge
  abort: case-folding collision between a and A
  [255]
  $ hg parents --template '{rev}\n'
  2
  $ hg status -A
  C A
  $ cat A
  A

test for deletion awareness of case-folding collision check (issue3648):
revision '#3' doesn't change 'a', so 'a' should be recognized as
safely removed in merging between #2 and #3.

  $ hg update --clean 3
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge 2
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg status -A
  M A
  R a
  C x

  $ hg update --clean 2
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge 3
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg status -A
  M x
  C A

  $ cd ..

Prepare for tests of directory case-folding collisions

  $ hg init directory-casing
  $ cd directory-casing
  $ touch 0 # test: file without directory
  $ mkdir 0a
  $ touch 0a/f
  $ mkdir aA
  $ touch aA/a
  $ hg ci -Aqm0

Directory/file case-folding collision:

  $ hg up -q null
  $ touch 00 # test: starts as '0'
  $ mkdir 000 # test: starts as '0'
  $ touch 000/f
  $ touch Aa # test: collision with 'aA/a'
  $ hg ci -Aqm1

  $ hg merge 0
  abort: case-folding collision between Aa and directory of aA/a
  [255]
(note: no collision between 0 and 00 or 000/f)

Directory case-folding collision:

  $ hg up -qC null
  $ hg --config extensions.purge= purge
  $ mkdir 0A0
  $ touch 0A0/f # test: starts as '0a'
  $ mkdir Aa
  $ touch Aa/b # test: collision with 'aA/a'
  $ hg ci -Aqm2

  $ hg merge 0
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cd ..

################################
test for linear updates
################################

test for rename awareness of case-folding collision check:

(1) colliding file is one renamed from collided file

  $ hg init linearupdate_renameaware_1
  $ cd linearupdate_renameaware_1

  $ echo a > a
  $ hg add a
  $ hg commit -m '#0'
  $ hg rename a tmp
  $ hg rename tmp A
  $ hg commit -m '#1'

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

  $ echo 'this is added line' >> a
  $ hg update 1
  merging a and A to A
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  $ hg status -A
  M A
  $ cat A
  a
  this is added line

  $ cd ..

(2) colliding file is not related to collided file

  $ hg init linearupdate_renameaware_2
  $ cd linearupdate_renameaware_2

  $ echo a > a
  $ hg add a
  $ hg commit -m '#0'
  $ hg remove a
  $ hg commit -m '#1'
  $ echo A > A
  $ hg add A
  $ hg commit -m '#2'

  $ hg update 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg parents --template '{rev}\n'
  0
  $ hg status -A
  C a
  $ cat A
  a
  $ hg up -qC 2

  $ hg update --check 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg parents --template '{rev}\n'
  0
  $ hg status -A
  C a
  $ cat a
  a

  $ hg update --clean 2
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg parents --template '{rev}\n'
  2
  $ hg status -A
  C A
  $ cat A
  A

  $ cd ..

(3) colliding file is not related to collided file: added in working dir

  $ hg init linearupdate_renameaware_3
  $ cd linearupdate_renameaware_3

  $ echo a > a
  $ hg add a
  $ hg commit -m '#0'
  $ hg rename a b
  $ hg commit -m '#1'
  $ hg update 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo B > B
  $ hg add B
  $ hg status
  A B
  $ hg update
  abort: case-folding collision between b and B
  [255]

  $ hg update --check
  abort: uncommitted changes
  [255]

  $ hg update --clean
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg parents --template '{rev}\n'
  1
  $ hg status -A
  C b
  $ cat b
  a

  $ cd ..