view tests/test-newbranch.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.

  $ branchcache=.hg/cache/branch2

  $ listbranchcaches() {
  >    for f in .hg/cache/branch2*;
  >       do echo === $f ===;
  >       cat $f;
  >     done;
  > }
  $ purgebranchcaches() {
  >     rm .hg/cache/branch2*
  > }

  $ hg init t
  $ cd t

  $ hg branches
  $ echo foo > a
  $ hg add a
  $ hg ci -m "initial"
  $ hg branch foo
  marked working directory as branch foo
  (branches are permanent and global, did you want a bookmark?)
  $ hg branch
  foo
  $ hg ci -m "add branch name"
  $ hg branch bar
  marked working directory as branch bar
  $ hg ci -m "change branch name"

Branch shadowing:

  $ hg branch default
  abort: a branch of the same name already exists
  (use 'hg update' to switch to it)
  [255]

  $ hg branch -f default
  marked working directory as branch default

  $ hg ci -m "clear branch name"
  created new head

There should be only one default branch head

  $ hg heads .
  changeset:   3:1c28f494dae6
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     clear branch name
  
Merging and branches

  $ hg co foo
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg branch
  foo

 set existing branch name fails unless force - setting existing parent branch works without force:

  $ hg branch bar
  abort: a branch of the same name already exists
  (use 'hg update' to switch to it)
  [255]

  $ hg branch -f bar
  marked working directory as branch bar

  $ hg branch foo
  marked working directory as branch foo

  $ echo bleah > a
  $ hg ci -m "modify a branch"

  $ hg merge default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg branch
  foo

 set existing branch name where branch head is ancestor:

  $ hg branch bar
  abort: a branch of the same name already exists
  (use 'hg update' to switch to it)
  [255]

 set (other) parent branch as branch name

  $ hg branch default
  marked working directory as branch default

 set (first) parent branch as branch name

  $ hg branch foo
  marked working directory as branch foo

  $ hg ci -m "merge"

  $ hg log -G -T '{rev}:{node|short} {branch} {desc}\n'
  @    5:530046499edf foo merge
  |\
  | o  4:adf1a74a7f7b foo modify a branch
  | |
  o |  3:1c28f494dae6 default clear branch name
  | |
  o |  2:c21617b13b22 bar change branch name
  |/
  o  1:6c0e42da283a foo add branch name
  |
  o  0:db01e8ea3388 default initial
  
  $ hg branches
  foo                            5:530046499edf
  default                        3:1c28f494dae6 (inactive)
  bar                            2:c21617b13b22 (inactive)

  $ hg branches -q
  foo
  default
  bar

Test for invalid branch cache:

  $ hg rollback
  repository tip rolled back to revision 4 (undo commit)
  working directory now based on revisions 4 and 3

  $ cp ${branchcache}-served .hg/bc-invalid

  $ hg log -r foo
  changeset:   4:adf1a74a7f7b
  branch:      foo
  tag:         tip
  parent:      1:6c0e42da283a
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify a branch
  
  $ cp .hg/bc-invalid $branchcache

  $ hg --debug log -r foo
  changeset:   4:adf1a74a7f7b4cd193d12992f5d0d6a004ed21d6
  branch:      foo
  tag:         tip
  phase:       draft
  parent:      1:6c0e42da283a56b5edc5b4fadb491365ec7f5fa8
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    1:8c342a37dfba0b3d3ce073562a00d8a813c54ffe
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       a
  extra:       branch=foo
  description:
  modify a branch
  
  
  $ purgebranchcaches
  $ echo corrupted > $branchcache

  $ hg log -qr foo
  4:adf1a74a7f7b

  $ listbranchcaches
  === .hg/cache/branch2 ===
  corrupted
  === .hg/cache/branch2-served ===
  adf1a74a7f7b4cd193d12992f5d0d6a004ed21d6 4
  c21617b13b220988e7a2e26290fbe4325ffa7139 o bar
  1c28f494dae69a2f8fc815059d257eccf3fcfe75 o default
  adf1a74a7f7b4cd193d12992f5d0d6a004ed21d6 o foo

Push should update the branch cache:

  $ hg init ../target

Pushing just rev 0:

  $ hg push -qr 0 ../target

  $ (cd ../target/; listbranchcaches)
  === .hg/cache/branch2-base ===
  db01e8ea3388fd3c7c94e1436ea2bd6a53d581c5 0
  db01e8ea3388fd3c7c94e1436ea2bd6a53d581c5 o default

Pushing everything:

  $ hg push -qf ../target

  $ (cd ../target/; listbranchcaches)
  === .hg/cache/branch2-base ===
  adf1a74a7f7b4cd193d12992f5d0d6a004ed21d6 4
  c21617b13b220988e7a2e26290fbe4325ffa7139 o bar
  1c28f494dae69a2f8fc815059d257eccf3fcfe75 o default
  adf1a74a7f7b4cd193d12992f5d0d6a004ed21d6 o foo

Update with no arguments: tipmost revision of the current branch:

  $ hg up -q -C 0
  $ hg up -q
  $ hg id
  1c28f494dae6

  $ hg up -q 1
  $ hg up -q
  $ hg id
  adf1a74a7f7b (foo) tip

  $ hg branch foobar
  marked working directory as branch foobar

  $ hg up
  abort: branch foobar not found
  [255]

Fast-forward merge:

  $ hg branch ff
  marked working directory as branch ff

  $ echo ff > ff
  $ hg ci -Am'fast forward'
  adding ff

  $ hg up foo
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ hg merge ff
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg branch
  foo
  $ hg commit -m'Merge ff into foo'
  $ hg parents
  changeset:   6:185ffbfefa30
  branch:      foo
  tag:         tip
  parent:      4:adf1a74a7f7b
  parent:      5:1a3c27dc5e11
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Merge ff into foo
  
  $ hg manifest
  a
  ff


Test merging, add 3 default heads and one test head:

  $ cd ..
  $ hg init merges
  $ cd merges
  $ echo a > a
  $ hg ci -Ama
  adding a

  $ echo b > b
  $ hg ci -Amb
  adding b

  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo c > c
  $ hg ci -Amc
  adding c
  created new head

  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo d > d
  $ hg ci -Amd
  adding d
  created new head

  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg branch test
  marked working directory as branch test
  (branches are permanent and global, did you want a bookmark?)
  $ echo e >> e
  $ hg ci -Ame
  adding e

  $ hg log
  changeset:   4:3a1e01ed1df4
  branch:      test
  tag:         tip
  parent:      0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     e
  
  changeset:   3:980f7dc84c29
  parent:      0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     d
  
  changeset:   2:d36c0562f908
  parent:      0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     c
  
  changeset:   1:d2ae7f538514
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     b
  
  changeset:   0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  
Implicit merge with test branch as parent:

  $ hg merge
  abort: branch 'test' has one head - please merge with an explicit rev
  (run 'hg heads' to see all heads)
  [255]
  $ hg up -C default
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

Implicit merge with default branch as parent:

  $ hg merge
  abort: branch 'default' has 3 heads - please merge with an explicit rev
  (run 'hg heads .' to see heads)
  [255]

3 branch heads, explicit merge required:

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

2 branch heads, implicit merge works:

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

  $ cd ..