view tests/test-resolve.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.

test that a commit clears the merge state.

  $ hg init repo
  $ cd repo

  $ echo foo > file1
  $ echo foo > file2
  $ hg commit -Am 'add files'
  adding file1
  adding file2

  $ echo bar >> file1
  $ echo bar >> file2
  $ hg commit -Am 'append bar to files'

create a second head with conflicting edits

  $ hg up -C 0
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo baz >> file1
  $ echo baz >> file2
  $ hg commit -Am 'append baz to files'
  created new head

create a third head with no conflicting edits
  $ hg up -qC 0
  $ echo foo > file3
  $ hg commit -Am 'add non-conflicting file'
  adding file3
  created new head

failing merge

  $ hg up -qC 2
  $ hg merge --tool=internal:fail 1
  0 files updated, 0 files merged, 0 files removed, 2 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

resolve -l should contain unresolved entries

  $ hg resolve -l
  U file1
  U file2

  $ hg resolve -l --no-status
  file1
  file2

resolving an unknown path should emit a warning, but not for -l

  $ hg resolve -m does-not-exist
  arguments do not match paths that need resolving
  $ hg resolve -l does-not-exist

resolve the failure

  $ echo resolved > file1
  $ hg resolve -m file1

resolve -l should show resolved file as resolved

  $ hg resolve -l
  R file1
  U file2

  $ hg resolve -l -Tjson
  [
   {
    "path": "file1",
    "status": "R"
   },
   {
    "path": "file2",
    "status": "U"
   }
  ]

resolve -m without paths should mark all resolved

  $ hg resolve -m
  (no more unresolved files)
  $ hg commit -m 'resolved'

resolve -l should be empty after commit

  $ hg resolve -l

  $ hg resolve -l -Tjson
  [
  ]

resolve --all should abort when no merge in progress

  $ hg resolve --all
  abort: resolve command not applicable when not merging
  [255]

resolve -m should abort when no merge in progress

  $ hg resolve -m
  abort: resolve command not applicable when not merging
  [255]

set up conflict-free merge

  $ hg up -qC 3
  $ hg merge 1
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

resolve --all should do nothing in merge without conflicts
  $ hg resolve --all
  (no more unresolved files)

resolve -m should do nothing in merge without conflicts

  $ hg resolve -m
  (no more unresolved files)

get back to conflicting state

  $ hg up -qC 2
  $ hg merge --tool=internal:fail 1
  0 files updated, 0 files merged, 0 files removed, 2 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

resolve without arguments should suggest --all
  $ hg resolve
  abort: no files or directories specified
  (use --all to remerge all files)
  [255]

resolve --all should re-merge all unresolved files
  $ hg resolve -q --all
  warning: conflicts during merge.
  merging file1 incomplete! (edit conflicts, then use 'hg resolve --mark')
  warning: conflicts during merge.
  merging file2 incomplete! (edit conflicts, then use 'hg resolve --mark')
  [1]
  $ grep '<<<' file1 > /dev/null
  $ grep '<<<' file2 > /dev/null

resolve <file> should re-merge file
  $ echo resolved > file1
  $ hg resolve -q file1
  warning: conflicts during merge.
  merging file1 incomplete! (edit conflicts, then use 'hg resolve --mark')
  [1]
  $ grep '<<<' file1 > /dev/null

resolve <file> should do nothing if 'file' was marked resolved
  $ echo resolved > file1
  $ hg resolve -m file1
  $ hg resolve -q file1
  $ cat file1
  resolved

test crashed merge with empty mergestate

  $ hg up -qC 1
  $ mkdir .hg/merge
  $ touch .hg/merge/state

resolve -l should be empty

  $ hg resolve -l

  $ cd ..