tests/test-histedit-obsolete.t

merge: minimize conflicts when common base is not shown (issue4447)

Previously, two changes that were nearly, but not quite, identical would result
in large merge conflict regions that looked very similar, and were thus very
confusing to users, and lead people used to other source control systems to
claim that "mercurial's merge algorithms suck". In the relatively common case
of a new file being introduced in two branches with very slight modifications,
the old behavior would show the entire file as a conflict, and it would be very
difficult for a user to determine what was going on.

In the past, mercurial attempted to solve this with a "very smart" algorithm
that would find all common lines, but this has significant problems as
described in 2ea6d906cf9b.

Instead, we use a "very dumb" algorithm introduced in the previous patch that
simply matches lines at the periphery of conflict regions. This minimizes most
conflict regions well, though there may still be some degenerate edge cases,
like small modification to the beginning and end of a large file.

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

Enable obsolete

  $ cat >> $HGRCPATH << EOF
  > [ui]
  > logtemplate= {rev}:{node|short} {desc|firstline}
  > [phases]
  > publish=False
  > [experimental]
  > evolution=createmarkers,allowunstable
  > [extensions]
  > histedit=
  > rebase=
  > EOF

  $ hg init base
  $ cd base

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

  $ hg log --graph
  @  5:652413bf663e f
  |
  o  4:e860deea161a e
  |
  o  3:055a42cdd887 d
  |
  o  2:177f92b77385 c
  |
  o  1:d2ae7f538514 b
  |
  o  0:cb9a9f314b8b 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:
  #
  #  e, edit = use commit, but stop for amending
  #  m, mess = edit commit message without changing commit content
  #  p, pick = use commit
  #  d, drop = remove commit from history
  #  f, fold = use commit, but combine it with the one above
  #  r, roll = like fold, but discard this commit's description
  #
  $ 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
  [1]
  $ hg log --graph --hidden
  @  10:cacdfd884a93 f
  |
  o  9:59d9f330561f d
  |
  | x  8:b558abc46d09 fold-temp-revision e860deea161a
  | |
  | x  7:96e494a2d553 d
  |/
  o  6:b346ab9a313d c
  |
  | x  5:652413bf663e f
  | |
  | x  4:e860deea161a e
  | |
  | x  3:055a42cdd887 d
  | |
  | x  2:177f92b77385 c
  | |
  | x  1:d2ae7f538514 b
  |/
  o  0:cb9a9f314b8b a
  
  $ hg debugobsolete
  96e494a2d553dd05902ba1cee1d94d4cb7b8faed 0 {b346ab9a313db8537ecf96fca3ca3ca984ef3bd7} (*) {'user': 'test'} (glob)
  b558abc46d09c30f57ac31e85a8a3d64d2e906e4 0 {96e494a2d553dd05902ba1cee1d94d4cb7b8faed} (*) {'user': 'test'} (glob)
  d2ae7f538514cd87c17547b0de4cea71fe1af9fb 0 {cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b} (*) {'user': 'test'} (glob)
  177f92b773850b59254aa5e923436f921b55483b b346ab9a313db8537ecf96fca3ca3ca984ef3bd7 0 (*) {'user': 'test'} (glob)
  055a42cdd88768532f9cf79daa407fc8d138de9b 59d9f330561fd6c88b1a6b32f0e45034d88db784 0 (*) {'user': 'test'} (glob)
  e860deea161a2f77de56603b340ebbb4536308ae 59d9f330561fd6c88b1a6b32f0e45034d88db784 0 (*) {'user': 'test'} (glob)
  652413bf663ef2a641cab26574e46d5f5a64a55a cacdfd884a9321ec4e1de275ef3949fa953a1f83 0 (*) {'user': 'test'} (glob)


Ensure hidden revision does not prevent histedit
-------------------------------------------------

create an hidden revision

  $ hg histedit 6 --commands - << EOF
  > pick b346ab9a313d 6 c
  > drop 59d9f330561f 7 d
  > pick cacdfd884a93 8 f
  > EOF
  $ hg log --graph
  @  11:c13eb81022ca f
  |
  o  6:b346ab9a313d c
  |
  o  0:cb9a9f314b8b a
  
check hidden revision are ignored (6 have hidden children 7 and 8)

  $ hg histedit 6 --commands - << EOF
  > pick b346ab9a313d 6 c
  > pick c13eb81022ca 8 f
  > EOF



Test that rewriting leaving instability behind is allowed
---------------------------------------------------------------------

  $ hg up '.^'
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg log -r 'children(.)'
  11:c13eb81022ca f (no-eol)
  $ hg histedit -r '.' --commands - <<EOF
  > edit b346ab9a313d 6 c
  > EOF
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  adding c
  Editing (b346ab9a313d), you may commit or record as needed now.
  (hg histedit --continue to resume)
  [1]
  $ echo c >> c
  $ hg histedit --continue

  $ hg log -r 'unstable()'
  11:c13eb81022ca f (no-eol)

stabilise

  $ hg rebase  -r 'unstable()' -d .
  rebasing 11:c13eb81022ca "f"
  $ hg up tip -q

Test dropping of changeset on the top of the stack
-------------------------------------------------------

Nothing is rewritten below, the working directory parent must be change for the
dropped changeset to be hidden.

  $ cd ..
  $ hg clone base droplast
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd droplast
  $ hg histedit -r '40db8afa467b' --commands - << EOF
  > pick 40db8afa467b 10 c
  > drop b449568bf7fc 11 f
  > EOF
  $ hg log -G
  @  12:40db8afa467b c
  |
  o  0:cb9a9f314b8b a
  

With rewritten ancestors

  $ echo e > e
  $ hg add e
  $ hg commit -m g
  $ echo f > f
  $ hg add f
  $ hg commit -m h
  $ hg histedit -r '40db8afa467b' --commands - << EOF
  > pick 47a8561c0449 12 g
  > pick 40db8afa467b 10 c
  > drop 1b3b05f35ff0 13 h
  > EOF
  $ hg log -G
  @  17:ee6544123ab8 c
  |
  o  16:269e713e9eae g
  |
  o  0:cb9a9f314b8b a
  
  $ cd ../base



Test phases support
===========================================

Check that histedit respect immutability
-------------------------------------------

  $ cat >> $HGRCPATH << EOF
  > [ui]
  > logtemplate= {rev}:{node|short} ({phase}) {desc|firstline}\n
  > EOF

  $ hg ph -pv '.^'
  phase changed for 2 changesets
  $ hg log -G
  @  13:b449568bf7fc (draft) f
  |
  o  12:40db8afa467b (public) c
  |
  o  0:cb9a9f314b8b (public) a
  
  $ hg histedit -r '.~2'
  abort: cannot edit public changeset: cb9a9f314b8b
  (see "hg help phases" for details)
  [255]


Prepare further testing
-------------------------------------------

  $ for x in g h i j k ; do
  >     echo $x > $x
  >     hg add $x
  >     hg ci -m $x
  > done
  $ hg phase --force --secret .~2
  $ hg log -G
  @  18:ee118ab9fa44 (secret) k
  |
  o  17:3a6c53ee7f3d (secret) j
  |
  o  16:b605fb7503f2 (secret) i
  |
  o  15:7395e1ff83bd (draft) h
  |
  o  14:6b70183d2492 (draft) g
  |
  o  13:b449568bf7fc (draft) f
  |
  o  12:40db8afa467b (public) c
  |
  o  0:cb9a9f314b8b (public) a
  
  $ cd ..

simple phase conservation
-------------------------------------------

Resulting changeset should conserve the phase of the original one whatever the
phases.new-commit option is.

New-commit as draft (default)

  $ cp -r base simple-draft
  $ cd simple-draft
  $ hg histedit -r 'b449568bf7fc' --commands - << EOF
  > edit b449568bf7fc 11 f
  > pick 6b70183d2492 12 g
  > pick 7395e1ff83bd 13 h
  > pick b605fb7503f2 14 i
  > pick 3a6c53ee7f3d 15 j
  > pick ee118ab9fa44 16 k
  > EOF
  0 files updated, 0 files merged, 6 files removed, 0 files unresolved
  adding f
  Editing (b449568bf7fc), you may commit or record as needed now.
  (hg histedit --continue to resume)
  [1]
  $ echo f >> f
  $ hg histedit --continue
  $ hg log -G
  @  24:12e89af74238 (secret) k
  |
  o  23:636a8687b22e (secret) j
  |
  o  22:ccaf0a38653f (secret) i
  |
  o  21:11a89d1c2613 (draft) h
  |
  o  20:c1dec7ca82ea (draft) g
  |
  o  19:087281e68428 (draft) f
  |
  o  12:40db8afa467b (public) c
  |
  o  0:cb9a9f314b8b (public) a
  
  $ cd ..


New-commit as draft (default)

  $ cp -r base simple-secret
  $ cd simple-secret
  $ cat >> .hg/hgrc << EOF
  > [phases]
  > new-commit=secret
  > EOF
  $ hg histedit -r 'b449568bf7fc' --commands - << EOF
  > edit b449568bf7fc 11 f
  > pick 6b70183d2492 12 g
  > pick 7395e1ff83bd 13 h
  > pick b605fb7503f2 14 i
  > pick 3a6c53ee7f3d 15 j
  > pick ee118ab9fa44 16 k
  > EOF
  0 files updated, 0 files merged, 6 files removed, 0 files unresolved
  adding f
  Editing (b449568bf7fc), you may commit or record as needed now.
  (hg histedit --continue to resume)
  [1]
  $ echo f >> f
  $ hg histedit --continue
  $ hg log -G
  @  24:12e89af74238 (secret) k
  |
  o  23:636a8687b22e (secret) j
  |
  o  22:ccaf0a38653f (secret) i
  |
  o  21:11a89d1c2613 (draft) h
  |
  o  20:c1dec7ca82ea (draft) g
  |
  o  19:087281e68428 (draft) f
  |
  o  12:40db8afa467b (public) c
  |
  o  0:cb9a9f314b8b (public) a
  
  $ cd ..


Changeset reordering
-------------------------------------------

If a secret changeset is put before a draft one, all descendant should be secret.
It seems more important to present the secret phase.

  $ cp -r base reorder
  $ cd reorder
  $ hg histedit -r 'b449568bf7fc' --commands - << EOF
  > pick b449568bf7fc 11 f
  > pick 3a6c53ee7f3d 15 j
  > pick 6b70183d2492 12 g
  > pick b605fb7503f2 14 i
  > pick 7395e1ff83bd 13 h
  > pick ee118ab9fa44 16 k
  > EOF
  $ hg log -G
  @  23:558246857888 (secret) k
  |
  o  22:28bd44768535 (secret) h
  |
  o  21:d5395202aeb9 (secret) i
  |
  o  20:21edda8e341b (secret) g
  |
  o  19:5ab64f3a4832 (secret) j
  |
  o  13:b449568bf7fc (draft) f
  |
  o  12:40db8afa467b (public) c
  |
  o  0:cb9a9f314b8b (public) a
  
  $ cd ..

Changeset folding
-------------------------------------------

Folding a secret changeset with a draft one turn the result secret (again,
better safe than sorry). Folding between same phase changeset still works

Note that there is a few reordering in this series for more extensive test

  $ cp -r base folding
  $ cd folding
  $ cat >> .hg/hgrc << EOF
  > [phases]
  > new-commit=secret
  > EOF
  $ hg histedit -r 'b449568bf7fc' --commands - << EOF
  > pick 7395e1ff83bd 13 h
  > fold b449568bf7fc 11 f
  > pick 6b70183d2492 12 g
  > fold 3a6c53ee7f3d 15 j
  > pick b605fb7503f2 14 i
  > fold ee118ab9fa44 16 k
  > EOF
  $ hg log -G
  @  27:f9daec13fb98 (secret) i
  |
  o  24:49807617f46a (secret) g
  |
  o  21:050280826e04 (draft) h
  |
  o  12:40db8afa467b (public) c
  |
  o  0:cb9a9f314b8b (public) a
  
  $ hg co 49807617f46a
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ echo wat >> wat
  $ hg add wat
  $ hg ci -m 'add wat'
  created new head
  $ hg merge f9daec13fb98
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m 'merge'
  $ echo not wat > wat
  $ hg ci -m 'modify wat'
  $ hg histedit 050280826e04
  abort: cannot edit history that contains merges
  [255]
  $ cd ..