view tests/test-rebase-mq.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=
  > mq=
  > 
  > [mq]
  > plain=true
  > 
  > [alias]
  > tglog = log -G --template "{rev}: '{desc}' tags: {tags}\n"
  > EOF


  $ hg init a
  $ cd a
  $ hg qinit -c

  $ echo c1 > f
  $ hg add f
  $ hg ci -m C1

  $ echo r1 > f
  $ hg ci -m R1

  $ hg up -q 0

  $ hg qnew f.patch -d '1 0'
  $ echo mq1 > f
  $ hg qref -m P0

  $ hg qnew f2.patch
  $ echo mq2 > f
  $ hg qref -m P1 -d '2 0'

  $ hg tglog
  @  3: 'P1' tags: f2.patch qtip tip
  |
  o  2: 'P0' tags: f.patch qbase
  |
  | o  1: 'R1' tags:
  |/
  o  0: 'C1' tags: qparent
  

Rebase - try to rebase on an applied mq patch:

  $ hg rebase -s 1 -d 3
  abort: cannot rebase onto an applied mq patch
  [255]

Rebase - same thing, but mq patch is default dest:

  $ hg up -q 1
  $ hg rebase
  abort: cannot rebase onto an applied mq patch
  [255]
  $ hg up -q qtip

Rebase - generate a conflict:

  $ hg rebase -s 2 -d 1
  rebasing 2:3504f44bffc0 "P0" (f.patch qbase)
  merging f
  warning: conflicts during merge.
  merging f incomplete! (edit conflicts, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

Fix the 1st conflict:

  $ echo mq1r1 > f
  $ hg resolve -m f
  (no more unresolved files)
  $ hg rebase -c
  rebasing 2:3504f44bffc0 "P0" (f.patch qbase)
  rebasing 3:929394423cd3 "P1" (f2.patch qtip tip)
  merging f
  warning: conflicts during merge.
  merging f incomplete! (edit conflicts, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

Fix the 2nd conflict:

  $ echo mq1r1mq2 > f
  $ hg resolve -m f
  (no more unresolved files)
  $ hg rebase -c
  already rebased 2:3504f44bffc0 "P0" (f.patch qbase) as ebe9914c0d1c
  rebasing 3:929394423cd3 "P1" (f2.patch qtip)
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/3504f44bffc0-30595b40-backup.hg (glob)

  $ hg tglog
  @  3: 'P1' tags: f2.patch qtip tip
  |
  o  2: 'P0' tags: f.patch qbase
  |
  o  1: 'R1' tags: qparent
  |
  o  0: 'C1' tags:
  
  $ hg up -q qbase

  $ cat f
  mq1r1

  $ cat .hg/patches/f.patch
  # HG changeset patch
  # User test
  # Date 1 0
  #      Thu Jan 01 00:00:01 1970 +0000
  # Node ID ebe9914c0d1c3f60096e952fa4dbb3d377dea3ab
  # Parent  bac9ed9960d8992bcad75864a879fa76cadaf1b0
  P0
  
  diff -r bac9ed9960d8 -r ebe9914c0d1c f
  --- a/f	Thu Jan 01 00:00:00 1970 +0000
  +++ b/f	Thu Jan 01 00:00:01 1970 +0000
  @@ -1,1 +1,1 @@
  -r1
  +mq1r1

Update to qtip:

  $ hg up -q qtip

  $ cat f
  mq1r1mq2

  $ cat .hg/patches/f2.patch
  # HG changeset patch
  # User test
  # Date 2 0
  #      Thu Jan 01 00:00:02 1970 +0000
  # Node ID 462012cf340c97d44d62377c985a423f6bb82f07
  # Parent  ebe9914c0d1c3f60096e952fa4dbb3d377dea3ab
  P1
  
  diff -r ebe9914c0d1c -r 462012cf340c f
  --- a/f	Thu Jan 01 00:00:01 1970 +0000
  +++ b/f	Thu Jan 01 00:00:02 1970 +0000
  @@ -1,1 +1,1 @@
  -mq1r1
  +mq1r1mq2

Adding one git-style patch and one normal:

  $ hg qpop -a
  popping f2.patch
  popping f.patch
  patch queue now empty

  $ rm -fr .hg/patches
  $ hg qinit -c

  $ hg up -q 0

  $ hg qnew --git f_git.patch -d '3 0'
  $ echo mq1 > p
  $ hg add p
  $ hg qref --git -m 'P0 (git)'

  $ hg qnew f.patch -d '4 0'
  $ echo mq2 > p
  $ hg qref -m P1
  $ hg qci -m 'save patch state'

  $ hg qseries -s
  f_git.patch: P0 (git)
  f.patch: P1

  $ hg -R .hg/patches manifest
  .hgignore
  f.patch
  f_git.patch
  series

  $ cat .hg/patches/f_git.patch
  Date: 3 0
  
  P0 (git)
  
  diff --git a/p b/p
  new file mode 100644
  --- /dev/null
  +++ b/p
  @@ -0,0 +1,1 @@
  +mq1

  $ cat .hg/patches/f.patch
  Date: 4 0
  
  P1
  
  diff -r ???????????? p (glob)
  --- a/p	??? ??? ?? ??:??:?? ???? ????? (glob)
  +++ b/p	??? ??? ?? ??:??:?? ???? ????? (glob)
  @@ -1,1 +1,1 @@
  -mq1
  +mq2


Rebase the applied mq patches:

  $ hg rebase -s 2 -d 1
  rebasing 2:0c587ffcb480 "P0 (git)" (f_git.patch qbase)
  rebasing 3:c7f18665e4bc "P1" (f.patch qtip tip)
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/0c587ffcb480-0ea5695f-backup.hg (glob)

  $ hg qci -m 'save patch state'

  $ hg qseries -s
  f_git.patch: P0 (git)
  f.patch: P1

  $ hg -R .hg/patches manifest
  .hgignore
  f.patch
  f_git.patch
  series

  $ cat .hg/patches/f_git.patch
  # HG changeset patch
  # User test
  # Date 3 0
  #      Thu Jan 01 00:00:03 1970 +0000
  # Node ID 12d9f6a3bbe560dee50c7c454d434add7fb8e837
  # Parent  bac9ed9960d8992bcad75864a879fa76cadaf1b0
  P0 (git)
  
  diff --git a/p b/p
  new file mode 100644
  --- /dev/null
  +++ b/p
  @@ -0,0 +1,1 @@
  +mq1

  $ cat .hg/patches/f.patch
  # HG changeset patch
  # User test
  # Date 4 0
  #      Thu Jan 01 00:00:04 1970 +0000
  # Node ID c77a2661c64c60d82f63c4f7aefd95b3a948a557
  # Parent  12d9f6a3bbe560dee50c7c454d434add7fb8e837
  P1
  
  diff -r 12d9f6a3bbe5 -r c77a2661c64c p
  --- a/p	Thu Jan 01 00:00:03 1970 +0000
  +++ b/p	Thu Jan 01 00:00:04 1970 +0000
  @@ -1,1 +1,1 @@
  -mq1
  +mq2

  $ cd ..

Rebase with guards

  $ hg init foo
  $ cd foo
  $ echo a > a
  $ hg ci -Am a
  adding a

Create mq repo with guarded patches foo and bar and empty patch:

  $ hg qinit
  $ echo guarded > guarded
  $ hg add guarded
  $ hg qnew guarded
  $ hg qnew empty-important -m 'important commit message' -d '1 0'
  $ echo bar > bar
  $ hg add bar
  $ hg qnew bar -d '2 0'
  $ echo foo > foo
  $ hg add foo
  $ hg qnew foo
  $ hg qpop -a
  popping foo
  popping bar
  popping empty-important
  popping guarded
  patch queue now empty
  $ hg qguard guarded +guarded
  $ hg qguard bar +baz
  $ hg qguard foo +baz
  $ hg qselect baz
  number of unguarded, unapplied patches has changed from 1 to 3
  $ hg qpush bar
  applying empty-important
  patch empty-important is empty
  applying bar
  now at: bar

  $ hg qguard -l
  guarded: +guarded
  empty-important: unguarded
  bar: +baz
  foo: +baz

  $ hg tglog
  @  2: 'imported patch bar' tags: bar qtip tip
  |
  o  1: 'important commit message' tags: empty-important qbase
  |
  o  0: 'a' tags: qparent
  
Create new head to rebase bar onto:

  $ hg up -C 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo b > b
  $ hg add b
  $ hg ci -m b
  created new head
  $ hg up -C 2
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo a >> a
  $ hg qref

  $ hg tglog
  @  3: '[mq]: bar' tags: bar qtip tip
  |
  | o  2: 'b' tags:
  | |
  o |  1: 'important commit message' tags: empty-important qbase
  |/
  o  0: 'a' tags: qparent
  

Rebase bar (make sure series order is preserved and empty-important also is
removed from the series):

  $ hg qseries
  guarded
  empty-important
  bar
  foo
  $ [ -f .hg/patches/empty-important ]
  $ hg -q rebase -d 2
  note: rebase of 1:0aaf4c3af7eb created no changes to commit
  $ hg qseries
  guarded
  bar
  foo
  $ [ -f .hg/patches/empty-important ]
  [1]

  $ hg qguard -l
  guarded: +guarded
  bar: +baz
  foo: +baz

  $ hg tglog
  @  2: '[mq]: bar' tags: bar qbase qtip tip
  |
  o  1: 'b' tags: qparent
  |
  o  0: 'a' tags:
  
  $ cd ..