view tests/test-merge1.t @ 25757:4d1382fd96ff

context: write dirstate out explicitly at the end of markcommitted

To detect change of a file without redundant comparison of file
content, dirstate recognizes a file as certainly clean, if:

  (1) it is already known as "normal",
  (2) dirstate entry for it has valid (= not "-1") timestamp, and
  (3) mode, size and timestamp of it on the filesystem are as same as
      ones expected in dirstate

This works as expected in many cases, but doesn't in the corner case
that changing a file keeps mode, size and timestamp of it on the
filesystem.

The timetable below shows steps in one of typical such situations:

  ---- ----------------------------------- ----------------
                                           timestamp of "f"
                                           ----------------
                                           dirstate   file-
  time          action                     mem  file  system
  ---- ----------------------------------- ---- ----- -----
   *                                             ***    ***
       - 'hg transplant REV1 REV2 ...'
         - transplanting REV1
           ....
   N
           - change "f", but keep size                   N
             (via 'patch.patch()')
           - 'dirstate.normal("f")'          N   ***
             (via 'repo.commit()')

         - transplanting REV2
           - change "f", but keep size                   N
             (via 'patch.patch()')
           - aborted while patching
  N+1
         - release wlock
           - 'dirstate.write()'              N    N      N

       - 'hg status' shows "r1" as "clean"   N    N      N
  ---- ----------------------------------- ---- ----- -----

The most important point is that 'dirstate.write()' is executed at N+1
or later. This causes writing dirstate timestamp N of "f" out
successfully. If it is executed at N, 'parsers.pack_dirstate()'
replaces timestamp N with "-1" before actual writing dirstate out.

This issue can occur when 'hg transplant' satisfies conditions below:

  - multiple revisions to be transplanted change the same file
  - those revisions don't change mode and size of the file, and
  - the 2nd or later revision of them fails after changing the file

The root cause of this issue is that files are changed without
flushing in-memory dirstate changes via 'repo.commit()' (even though
omitting 'dirstate.normallookup()' on files changed by 'patch.patch()'
for efficiency also causes this issue).

To detect changes of files correctly, this patch writes in-memory
dirstate changes out explicitly after marking files as clean in
'committablectx.markcommitted()', which is invoked via
'repo.commit()'.

After this change, timetable is changed as below:

  ---- ----------------------------------- ----------------
                                           timestamp of "f"
                                           ----------------
                                           dirstate   file-
  time          action                     mem  file  system
  ---- ----------------------------------- ---- ----- -----
   *                                             ***    ***
       - 'hg transplant REV1 REV2 ...'
         - transplanting REV1
           ....
   N
           - change "f", but keep size                   N
             (via 'patch.patch()')
           - 'dirstate.normal("f")'          N    ***
             (via 'repo.commit()')
       ----------------------------------- ---- ----- -----
           - 'dirsttate.write()'            -1    -1
       ----------------------------------- ---- ----- -----
         - transplanting REV2
           - change "f", but keep size                   N
             (via 'patch.patch()')
           - aborted while patching
  N+1
         - release wlock
           - 'dirstate.write()'              -1   -1     N

       - 'hg status' shows "r1" as "clean"   -1   -1     N
  ---- ----------------------------------- ---- ----- -----

To reproduce this issue in tests certainly, this patch emulates some
timing critical actions as below:

  - change "f" at N

    'patch.patch()' with 'fakepatchtime.py' explicitly changes mtime
    of patched files to "2000-01-01 00:00" (= N).

  - 'dirstate.write()' via 'repo.commit()' at N

    'fakedirstatewritetime.py' forces 'pack_dirstate()' to use
    "2000-01-01 00:00" as "now", only if 'pack_dirstate()' is invoked
    via 'committablectx.markcommitted()'.

  - 'dirstate.write()' via releasing wlock at N+1 (or "not at N")

    'pack_dirstate()' via releasing wlock uses actual timestamp at
    runtime as "now", and it should be different from the "2000-01-01
    00:00" of "f".

BTW, this patch doesn't test cases below, even though 'patch.patch()'
is used similarly in these cases:

  1. failure of 'hg import' or 'hg qpush'

  2. success of 'hg import', 'hg qpush' or 'hg transplant'

Case (1) above doesn't cause this kind of issue, because:

  - if patching is aborted by conflicts, changed files are committed

    changed files are marked as CLEAN, even though they are partially
    patched.

  - otherwise, dirstate are fully restored by 'dirstateguard'

    For example in timetable above, timestamp of "f" in .hg/dirstate
    is restored to -1 (or less than N), and subsequent 'hg status' can
    detect changes correctly.

Case (2) always causes 'repo.status()' invocation via 'repo.commit()'
just after changing files inside same wlock scope.

  ---- ----------------------------------- ----------------
                                           timestamp of "f"
                                           ----------------
                                           dirstate   file-
  time          action                     mem  file  system
  ---- ----------------------------------- ---- ----- -----
  N                                              ***   ***
       - make file "f" clean                            N

       - execute 'hg foobar'
         ....
         - 'dirstate.normal("f")'           N    ***
           (e.g. via dirty check
            or previous 'repo.commit()')

         - change "f", but keep size                    N
         - 'repo.status()' (*1)
           (via 'repo.commit()')
  ---- ----------------------------------- ---- ----- -----

At a glance, 'repo.status()' at (*1) seems to cause similar issue (=
"changed files are treated as clean"), but actually doesn't.

'dirstate._lastnormaltime' should be N at (*1) above, because
'dirstate.normal()' via dirty check is finished at N.

Therefore, "f" changed at N (= 'dirstate._lastnormaltime') is forcibly
treated as "unsure" at (*1), and changes are detected as expected (see
'dirstate.status()' for detail).

If 'hg import' is executed with '--no-commit', 'repo.status()' isn't
invoked just after changing files inside same wlock scope.

But preceding 'dirstate.normal()' is invoked inside another wlock
scope via 'cmdutil.bailifchanged()', and in-memory changes should be
flushed at the end of that scope.

Therefore, timestamp N of clean "f" should be replaced by -1, if
'dirstate.write()' is invoked at N. It means that condition of this
issue isn't satisfied.

  $ cat <<EOF > merge
  > import sys, os
  > 
  > try:
  >     import msvcrt
  >     msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
  >     msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY)
  > except ImportError:
  >     pass
  > 
  > print "merging for", os.path.basename(sys.argv[1])
  > EOF
  $ HGMERGE="python ../merge"; export HGMERGE

  $ hg init t
  $ cd t
  $ echo This is file a1 > a
  $ hg add a
  $ hg commit -m "commit #0"
  $ echo This is file b1 > b
  $ hg add b
  $ hg commit -m "commit #1"

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

Test interrupted updates by exploiting our non-handling of directory collisions

  $ mkdir b
  $ hg up
  abort: *: '$TESTTMP/t/b' (glob)
  [255]
  $ hg ci
  abort: last update was interrupted
  (use 'hg update' to get a consistent checkout)
  [255]
  $ hg sum
  parent: 0:538afb845929 
   commit #0
  branch: default
  commit: (interrupted update)
  update: 1 new changesets (update)
  phases: 2 draft
  $ rmdir b
  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg sum
  parent: 1:b8bb4a988f25 tip
   commit #1
  branch: default
  commit: (clean)
  update: (current)
  phases: 2 draft

Prepare a basic merge

  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo This is file c1 > c
  $ hg add c
  $ hg commit -m "commit #2"
  created new head
  $ echo This is file b1 > b
no merges expected
  $ hg merge -P 1
  changeset:   1:b8bb4a988f25
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     commit #1
  
  $ hg merge 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg diff --nodates
  diff -r 49035e18a8e6 b
  --- /dev/null
  +++ b/b
  @@ -0,0 +1,1 @@
  +This is file b1
  $ hg status
  M b
  $ cd ..; rm -r t

  $ hg init t
  $ cd t
  $ echo This is file a1 > a
  $ hg add a
  $ hg commit -m "commit #0"
  $ echo This is file b1 > b
  $ hg add b
  $ hg commit -m "commit #1"

  $ hg update 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo This is file c1 > c
  $ hg add c
  $ hg commit -m "commit #2"
  created new head
  $ echo This is file b2 > b
merge should fail
  $ hg merge 1
  b: untracked file differs
  abort: untracked files in working directory differ from files in requested revision
  [255]
merge of b expected
  $ hg merge -f 1
  merging b
  merging for b
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg diff --nodates
  diff -r 49035e18a8e6 b
  --- /dev/null
  +++ b/b
  @@ -0,0 +1,1 @@
  +This is file b2
  $ hg status
  M b
  $ cd ..; rm -r t

  $ hg init t
  $ cd t
  $ echo This is file a1 > a
  $ hg add a
  $ hg commit -m "commit #0"
  $ echo This is file b1 > b
  $ hg add b
  $ hg commit -m "commit #1"
  $ echo This is file b22 > b
  $ hg commit -m "commit #2"
  $ hg update 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo This is file c1 > c
  $ hg add c
  $ hg commit -m "commit #3"
  created new head

Contents of b should be "this is file b1"
  $ cat b
  This is file b1

  $ echo This is file b22 > b
merge fails
  $ hg merge 2
  abort: uncommitted changes
  (use 'hg status' to list changes)
  [255]
merge expected!
  $ hg merge -f 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg diff --nodates
  diff -r 85de557015a8 b
  --- a/b
  +++ b/b
  @@ -1,1 +1,1 @@
  -This is file b1
  +This is file b22
  $ hg status
  M b
  $ cd ..; rm -r t

  $ hg init t
  $ cd t
  $ echo This is file a1 > a
  $ hg add a
  $ hg commit -m "commit #0"
  $ echo This is file b1 > b
  $ hg add b
  $ hg commit -m "commit #1"
  $ echo This is file b22 > b
  $ hg commit -m "commit #2"
  $ hg update 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo This is file c1 > c
  $ hg add c
  $ hg commit -m "commit #3"
  created new head
  $ echo This is file b33 > b
merge of b should fail
  $ hg merge 2
  abort: uncommitted changes
  (use 'hg status' to list changes)
  [255]
merge of b expected
  $ hg merge -f 2
  merging b
  merging for b
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg diff --nodates
  diff -r 85de557015a8 b
  --- a/b
  +++ b/b
  @@ -1,1 +1,1 @@
  -This is file b1
  +This is file b33
  $ hg status
  M b

Test for issue2364

  $ hg up -qC .
  $ hg rm b
  $ hg ci -md
  $ hg revert -r -2 b
  $ hg up -q -- -2

Test that updated files are treated as "modified", when
'merge.update()' is aborted before 'merge.recordupdates()' (= parents
aren't changed), even if none of mode, size and timestamp of them
isn't changed on the filesystem (see also issue4583).

  $ cat > $TESTTMP/abort.py <<EOF
  > # emulate aborting before "recordupdates()". in this case, files
  > # are changed without updating dirstate
  > from mercurial import extensions, merge, util
  > def applyupdates(orig, *args, **kwargs):
  >     orig(*args, **kwargs)
  >     raise util.Abort('intentional aborting')
  > def extsetup(ui):
  >     extensions.wrapfunction(merge, "applyupdates", applyupdates)
  > EOF

  $ cat >> .hg/hgrc <<EOF
  > [fakedirstatewritetime]
  > # emulate invoking dirstate.write() via repo.status()
  > # at 2000-01-01 00:00
  > fakenow = 200001010000
  > EOF

(file gotten from other revision)

  $ hg update -q -C 2
  $ echo 'THIS IS FILE B5' > b
  $ hg commit -m 'commit #5'

  $ hg update -q -C 3
  $ cat b
  This is file b1
  $ touch -t 200001010000 b
  $ hg debugrebuildstate

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > fakedirstatewritetime = $TESTDIR/fakedirstatewritetime.py
  > abort = $TESTTMP/abort.py
  > EOF
  $ hg merge 5
  abort: intentional aborting
  [255]
  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > fakedirstatewritetime = !
  > abort = !
  > EOF

  $ cat b
  THIS IS FILE B5
  $ touch -t 200001010000 b
  $ hg status -A b
  M b

(file merged from other revision)

  $ hg update -q -C 3
  $ echo 'this is file b6' > b
  $ hg commit -m 'commit #6'
  created new head

  $ cat b
  this is file b6
  $ touch -t 200001010000 b
  $ hg debugrebuildstate

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > fakedirstatewritetime = $TESTDIR/fakedirstatewritetime.py
  > abort = $TESTTMP/abort.py
  > EOF
  $ hg merge --tool internal:other 5
  abort: intentional aborting
  [255]
  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > fakedirstatewritetime = !
  > abort = !
  > EOF

  $ cat b
  THIS IS FILE B5
  $ touch -t 200001010000 b
  $ hg status -A b
  M b

  $ cd ..