view tests/test-rebase-rename.t @ 26375:3686fa2b8eee

windows: insert file positioning call between reads and writes

fopen() and fdopen() have a unique-to-Windows requirement that
transitions between read and write operations in files opened
in modes r+, w+, and a+ perform a file positioning call
(fsetpos, fseek, or rewind) in between. While the MSDN docs don't
say what will happen if this is not done, observations reveal
that Python raises an IOError with errno 0. Furthermore, I
/think/ this behavior isn't deterministic. But I can reproduce
it reliably with subsequent patches applied that open revlogs
in a+ mode and perform both reads and writes.

This patch introduces a proxy class for file handles opened
in r+, w+, and a+ mode on Windows. The class intercepts calls
and audits whether a file positioning function has been called
between read and write operations. If not, a dummy, no-op seek
to the current file position is performed. This appears to be
sufficient to "trick" Windows into allowing transitions between
read and writes without raising errors.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > 
  > [alias]
  > tlog  = log  --template "{rev}: '{desc}' {branches}\n"
  > tglog = tlog --graph
  > EOF


  $ hg init a
  $ cd a

  $ mkdir d
  $ echo a > a
  $ hg ci -Am A
  adding a

  $ echo b > d/b
  $ hg ci -Am B
  adding d/b

  $ hg mv d d-renamed
  moving d/b to d-renamed/b (glob)
  $ hg ci -m 'rename B'

  $ hg up -q -C 1

  $ hg mv a a-renamed
  $ echo x > d/x
  $ hg add d/x

  $ hg ci -m 'rename A'
  created new head

  $ hg tglog
  @  3: 'rename A'
  |
  | o  2: 'rename B'
  |/
  o  1: 'B'
  |
  o  0: 'A'
  

Rename is tracked:

  $ hg tlog -p --git -r tip
  3: 'rename A' 
  diff --git a/a b/a-renamed
  rename from a
  rename to a-renamed
  diff --git a/d/x b/d/x
  new file mode 100644
  --- /dev/null
  +++ b/d/x
  @@ -0,0 +1,1 @@
  +x
  
Rebase the revision containing the rename:

  $ hg rebase -s 3 -d 2
  rebasing 3:73a3ee40125d "rename A" (tip)
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/73a3ee40125d-1d78ebcf-backup.hg (glob)

  $ hg tglog
  @  3: 'rename A'
  |
  o  2: 'rename B'
  |
  o  1: 'B'
  |
  o  0: 'A'
  

Rename is not lost:

  $ hg tlog -p --git -r tip
  3: 'rename A' 
  diff --git a/a b/a-renamed
  rename from a
  rename to a-renamed
  diff --git a/d-renamed/x b/d-renamed/x
  new file mode 100644
  --- /dev/null
  +++ b/d-renamed/x
  @@ -0,0 +1,1 @@
  +x
  

Rebased revision does not contain information about b (issue3739)

  $ hg log -r 3 --debug
  changeset:   3:032a9b75e83bff1dcfb6cbfa4ef50a704bf1b569
  tag:         tip
  phase:       draft
  parent:      2:220d0626d185f372d9d8f69d9c73b0811d7725f7
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    3:035d66b27a1b06b2d12b46d41a39adb7a200c370
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files+:      a-renamed d-renamed/x
  files-:      a
  extra:       branch=default
  extra:       rebase_source=73a3ee40125d6f0f347082e5831ceccb3f005f8a
  description:
  rename A
  
  

  $ cd ..


  $ hg init b
  $ cd b

  $ echo a > a
  $ hg ci -Am A
  adding a

  $ echo b > b
  $ hg ci -Am B
  adding b

  $ hg cp b b-copied
  $ hg ci -Am 'copy B'

  $ hg up -q -C 1

  $ hg cp a a-copied
  $ hg ci -m 'copy A'
  created new head

  $ hg tglog
  @  3: 'copy A'
  |
  | o  2: 'copy B'
  |/
  o  1: 'B'
  |
  o  0: 'A'
  
Copy is tracked:

  $ hg tlog -p --git -r tip
  3: 'copy A' 
  diff --git a/a b/a-copied
  copy from a
  copy to a-copied
  
Rebase the revision containing the copy:

  $ hg rebase -s 3 -d 2
  rebasing 3:0a8162ff18a8 "copy A" (tip)
  saved backup bundle to $TESTTMP/b/.hg/strip-backup/0a8162ff18a8-dd06302a-backup.hg (glob)

  $ hg tglog
  @  3: 'copy A'
  |
  o  2: 'copy B'
  |
  o  1: 'B'
  |
  o  0: 'A'
  

Copy is not lost:

  $ hg tlog -p --git -r tip
  3: 'copy A' 
  diff --git a/a b/a-copied
  copy from a
  copy to a-copied
  

Rebased revision does not contain information about b (issue3739)

  $ hg log -r 3 --debug
  changeset:   3:98f6e6dbf45ab54079c2237fbd11066a5c41a11d
  tag:         tip
  phase:       draft
  parent:      2:39e588434882ff77d01229d169cdc77f29e8855e
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    3:2232f329d66fffe3930d43479ae624f66322b04d
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files+:      a-copied
  extra:       branch=default
  extra:       rebase_source=0a8162ff18a8900df8df8ef7ac0046955205613e
  description:
  copy A
  
  

  $ cd ..


Test rebase across repeating renames:

  $ hg init repo

  $ cd repo

  $ echo testing > file1.txt
  $ hg add file1.txt
  $ hg ci -m "Adding file1"

  $ hg rename file1.txt file2.txt
  $ hg ci -m "Rename file1 to file2"

  $ echo Unrelated change > unrelated.txt
  $ hg add unrelated.txt
  $ hg ci -m "Unrelated change"

  $ hg rename file2.txt file1.txt
  $ hg ci -m "Rename file2 back to file1"

  $ hg update -r -2
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo Another unrelated change >> unrelated.txt
  $ hg ci -m "Another unrelated change"
  created new head

  $ hg tglog
  @  4: 'Another unrelated change'
  |
  | o  3: 'Rename file2 back to file1'
  |/
  o  2: 'Unrelated change'
  |
  o  1: 'Rename file1 to file2'
  |
  o  0: 'Adding file1'
  

  $ hg rebase -s 4 -d 3
  rebasing 4:b918d683b091 "Another unrelated change" (tip)
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/b918d683b091-3024bc57-backup.hg (glob)

  $ hg diff --stat -c .
   unrelated.txt |  1 +
   1 files changed, 1 insertions(+), 0 deletions(-)

  $ cd ..

Verify that copies get preserved (issue4192).
  $ hg init copy-gets-preserved
  $ cd copy-gets-preserved

  $ echo a > a
  $ hg add a
  $ hg commit --message "File a created"
  $ hg copy a b
  $ echo b > b
  $ hg commit --message "File b created as copy of a and modified"
  $ hg copy b c
  $ echo c > c
  $ hg commit --message "File c created as copy of b and modified"
  $ hg copy c d
  $ echo d > d
  $ hg commit --message "File d created as copy of c and modified"

Note that there are four entries in the log for d
  $ hg tglog --follow d
  @  3: 'File d created as copy of c and modified'
  |
  o  2: 'File c created as copy of b and modified'
  |
  o  1: 'File b created as copy of a and modified'
  |
  o  0: 'File a created'
  
Update back to before we performed copies, and inject an unrelated change.
  $ hg update 0
  0 files updated, 0 files merged, 3 files removed, 0 files unresolved

  $ echo unrelated > unrelated
  $ hg add unrelated
  $ hg commit --message "Unrelated file created"
  created new head
  $ hg update 4
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

Rebase the copies on top of the unrelated change.
  $ hg rebase --source 1 --dest 4
  rebasing 1:79d255d24ad2 "File b created as copy of a and modified"
  rebasing 2:327f772bc074 "File c created as copy of b and modified"
  rebasing 3:421b7e82bb85 "File d created as copy of c and modified"
  saved backup bundle to $TESTTMP/copy-gets-preserved/.hg/strip-backup/79d255d24ad2-a2265555-backup.hg (glob)
  $ hg update 4
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

There should still be four entries in the log for d
  $ hg tglog --follow d
  @  4: 'File d created as copy of c and modified'
  |
  o  3: 'File c created as copy of b and modified'
  |
  o  2: 'File b created as copy of a and modified'
  |
  o  0: 'File a created'
  
Same steps as above, but with --collapse on rebase to make sure the
copy records collapse correctly.
  $ hg co 1
  0 files updated, 0 files merged, 3 files removed, 0 files unresolved
  $ echo more >> unrelated
  $ hg ci -m 'unrelated commit is unrelated'
  created new head
  $ hg rebase -s 2 --dest 5 --collapse
  rebasing 2:68bf06433839 "File b created as copy of a and modified"
  note: rebase of 2:68bf06433839 created no changes to commit
  rebasing 3:af74b229bc02 "File c created as copy of b and modified"
  merging b and c to c
  note: rebase of 3:af74b229bc02 created no changes to commit
  rebasing 4:dbb9ba033561 "File d created as copy of c and modified"
  merging c and d to d
  note: rebase of 4:dbb9ba033561 created no changes to commit
  saved backup bundle to $TESTTMP/copy-gets-preserved/.hg/strip-backup/68bf06433839-dde37595-backup.hg (glob)
  $ hg co tip
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

This should show both revision 3 and 0 since 'd' was transitively a
copy of 'a'.

  $ hg tglog --follow d
  @  3: 'Collapsed revision
  |  * File b created as copy of a and modified
  |  * File c created as copy of b and modified
  |  * File d created as copy of c and modified'
  o  0: 'File a created'
  

  $ cd ..