view tests/test-histedit-bookmark-motion.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.

  $ . "$TESTDIR/histedit-helpers.sh"

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > histedit=
  > EOF

  $ hg init r
  $ cd r

  $ for x in a b c d e f ; do
  >     echo $x > $x
  >     hg add $x
  >     hg ci -m $x
  > done

  $ hg book -r 1 will-move-backwards
  $ hg book -r 2 two
  $ hg book -r 2 also-two
  $ hg book -r 3 three
  $ hg book -r 4 four
  $ hg book -r tip five
  $ hg log --graph
  @  changeset:   5:652413bf663e
  |  bookmark:    five
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     f
  |
  o  changeset:   4:e860deea161a
  |  bookmark:    four
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     e
  |
  o  changeset:   3:055a42cdd887
  |  bookmark:    three
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     d
  |
  o  changeset:   2:177f92b77385
  |  bookmark:    also-two
  |  bookmark:    two
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     c
  |
  o  changeset:   1:d2ae7f538514
  |  bookmark:    will-move-backwards
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     b
  |
  o  changeset:   0:cb9a9f314b8b
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  
  $ HGEDITOR=cat hg histedit 1
  pick d2ae7f538514 1 b
  pick 177f92b77385 2 c
  pick 055a42cdd887 3 d
  pick e860deea161a 4 e
  pick 652413bf663e 5 f
  
  # Edit history between d2ae7f538514 and 652413bf663e
  #
  # Commits are listed from least to most recent
  #
  # Commands:
  #  p, pick = use commit
  #  e, edit = use commit, but stop for amending
  #  f, fold = use commit, but combine it with the one above
  #  r, roll = like fold, but discard this commit's description
  #  d, drop = remove commit from history
  #  m, mess = edit message without changing commit content
  #
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg histedit 1 --commands - --verbose << EOF | grep histedit
  > pick 177f92b77385 2 c
  > drop d2ae7f538514 1 b
  > pick 055a42cdd887 3 d
  > fold e860deea161a 4 e
  > pick 652413bf663e 5 f
  > EOF
  histedit: moving bookmarks also-two from 177f92b77385 to b346ab9a313d
  histedit: moving bookmarks five from 652413bf663e to cacdfd884a93
  histedit: moving bookmarks four from e860deea161a to 59d9f330561f
  histedit: moving bookmarks three from 055a42cdd887 to 59d9f330561f
  histedit: moving bookmarks two from 177f92b77385 to b346ab9a313d
  histedit: moving bookmarks will-move-backwards from d2ae7f538514 to cb9a9f314b8b
  saved backup bundle to $TESTTMP/r/.hg/strip-backup/d2ae7f538514-48787b8d-backup.hg (glob)
  saved backup bundle to $TESTTMP/r/.hg/strip-backup/96e494a2d553-3c6c5d92-backup.hg (glob)
  $ hg log --graph
  @  changeset:   3:cacdfd884a93
  |  bookmark:    five
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     f
  |
  o  changeset:   2:59d9f330561f
  |  bookmark:    four
  |  bookmark:    three
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     d
  |
  o  changeset:   1:b346ab9a313d
  |  bookmark:    also-two
  |  bookmark:    two
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     c
  |
  o  changeset:   0:cb9a9f314b8b
     bookmark:    will-move-backwards
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  
  $ HGEDITOR=cat hg histedit 1
  pick b346ab9a313d 1 c
  pick 59d9f330561f 2 d
  pick cacdfd884a93 3 f
  
  # Edit history between b346ab9a313d and cacdfd884a93
  #
  # Commits are listed from least to most recent
  #
  # Commands:
  #  p, pick = use commit
  #  e, edit = use commit, but stop for amending
  #  f, fold = use commit, but combine it with the one above
  #  r, roll = like fold, but discard this commit's description
  #  d, drop = remove commit from history
  #  m, mess = edit message without changing commit content
  #
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg histedit 1 --commands - --verbose << EOF | grep histedit
  > pick b346ab9a313d 1 c
  > pick cacdfd884a93 3 f
  > pick 59d9f330561f 2 d
  > EOF
  histedit: moving bookmarks five from cacdfd884a93 to c04e50810e4b
  histedit: moving bookmarks four from 59d9f330561f to c04e50810e4b
  histedit: moving bookmarks three from 59d9f330561f to c04e50810e4b
  saved backup bundle to $TESTTMP/r/.hg/strip-backup/59d9f330561f-073008af-backup.hg (glob)

We expect 'five' to stay at tip, since the tipmost bookmark is most
likely the useful signal.

  $ hg log --graph
  @  changeset:   3:c04e50810e4b
  |  bookmark:    five
  |  bookmark:    four
  |  bookmark:    three
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     d
  |
  o  changeset:   2:c13eb81022ca
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     f
  |
  o  changeset:   1:b346ab9a313d
  |  bookmark:    also-two
  |  bookmark:    two
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     c
  |
  o  changeset:   0:cb9a9f314b8b
     bookmark:    will-move-backwards
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a