annotate tests/test-merge-types.t @ 28029:72072cfc7e91

update: warn about other topological heads on bare update

A concern around the user experience of Mercurial is user getting stuck on there
own topological branch forever. For example, someone pulling another topological
branch, missing that message in pull asking them to merge and getting stuck on
there own local branch.

The current way to "address" this concern was for bare 'hg update' to target the
tipmost (also latest pulled) changesets and complain when the update was not
linear. That way, failure to merge newly pulled changesets would result in some
kind of failure.

Yet the failure was quite obscure, not working in all cases (eg: commit right
after pull) and the behavior was very impractical in the common case
(eg: issue4673).

To be able to change that behavior, we need to provide other ways to alert a
user stucks on one of many topological head. We do so with an extra message after
bare update:

  1 other heads for branch "default"

Bookmark get its own special version:

  1 other divergent bookmarks for "foobar"

There is significant room to improve the message itself, and we should augment
it with hint about how to see theses other heads or handle the situation (see
in-line comment). But having "a" message is already a significant improvement
compared to the existing situation. Once we have it we can iterate on a better
version of it. As having such message is an important step toward changing the
default destination for update and other nicety, I would like to move forward
quickly on getting such message.

This was discussed during London - October 2015 Sprint.

#require symlink execbit

  $ tellmeabout() {
  > if [ -h $1 ]; then
  >     echo $1 is a symlink:
  >     $TESTDIR/readlink.py $1
  > elif [ -x $1 ]; then
  >     echo $1 is an executable file with content:
  >     cat $1
  > else
  >     echo $1 is a plain file with content:
  >     cat $1
  > fi
  > }

  $ hg init test1
  $ cd test1

  $ echo a > a
  $ hg ci -Aqmadd
  $ chmod +x a
  $ hg ci -mexecutable

  $ hg up -q 0
  $ rm a
  $ ln -s symlink a
  $ hg ci -msymlink
  created new head

Symlink is local parent, executable is other:

  $ hg merge --debug
    searching for copies back to rev 1
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: c334dc3be0da, local: 521a1e40188f+, remote: 3574f3e69b1c
   preserving a for resolve of a
   a: versions differ -> m (premerge)
  picked tool ':merge' for a (binary False symlink True changedelete False)
  merging a
  my a@521a1e40188f+ other a@3574f3e69b1c ancestor a@c334dc3be0da
  warning: internal :merge cannot merge symlinks for a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ tellmeabout a
  a is a symlink:
  a -> symlink
  $ hg resolve a --tool internal:other
  (no more unresolved files)
  $ tellmeabout a
  a is an executable file with content:
  a
  $ hg st
  M a
  ? a.orig

Symlink is other parent, executable is local:

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

  $ hg merge --debug --tool :union
    searching for copies back to rev 1
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: c334dc3be0da, local: 3574f3e69b1c+, remote: 521a1e40188f
   preserving a for resolve of a
   a: versions differ -> m (premerge)
  picked tool ':union' for a (binary False symlink True changedelete False)
  merging a
  my a@3574f3e69b1c+ other a@521a1e40188f ancestor a@c334dc3be0da
  warning: internal :union cannot merge symlinks for a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ tellmeabout a
  a is an executable file with content:
  a

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

  $ hg merge --debug --tool :merge3
    searching for copies back to rev 1
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: c334dc3be0da, local: 3574f3e69b1c+, remote: 521a1e40188f
   preserving a for resolve of a
   a: versions differ -> m (premerge)
  picked tool ':merge3' for a (binary False symlink True changedelete False)
  merging a
  my a@3574f3e69b1c+ other a@521a1e40188f ancestor a@c334dc3be0da
  warning: internal :merge3 cannot merge symlinks for a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ tellmeabout a
  a is an executable file with content:
  a

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

  $ hg merge --debug --tool :merge-local
    searching for copies back to rev 1
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: c334dc3be0da, local: 3574f3e69b1c+, remote: 521a1e40188f
   preserving a for resolve of a
   a: versions differ -> m (premerge)
  picked tool ':merge-local' for a (binary False symlink True changedelete False)
  merging a
  my a@3574f3e69b1c+ other a@521a1e40188f ancestor a@c334dc3be0da
  warning: internal :merge-local cannot merge symlinks for a
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ tellmeabout a
  a is an executable file with content:
  a

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

  $ hg merge --debug --tool :merge-other
    searching for copies back to rev 1
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: c334dc3be0da, local: 3574f3e69b1c+, remote: 521a1e40188f
   preserving a for resolve of a
   a: versions differ -> m (premerge)
  picked tool ':merge-other' for a (binary False symlink True changedelete False)
  merging a
  my a@3574f3e69b1c+ other a@521a1e40188f ancestor a@c334dc3be0da
  warning: internal :merge-other cannot merge symlinks for a
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ tellmeabout a
  a is an executable file with content:
  a

Update to link without local change should get us a symlink (issue3316):

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  1 other heads for branch "default"
  $ hg st
  ? a.orig

Update to link with local change should cause a merge prompt (issue3200):

  $ hg up -Cq 0
  $ echo data > a
  $ HGMERGE= hg up -y --debug
    searching for copies back to rev 2
  resolving manifests
   branchmerge: False, force: False, partial: False
   ancestor: c334dc3be0da, local: c334dc3be0da+, remote: 521a1e40188f
   preserving a for resolve of a
   a: versions differ -> m (premerge)
  (couldn't find merge tool hgmerge|tool hgmerge can't handle symlinks) (re)
  picked tool ':prompt' for a (binary False symlink True changedelete False)
  no tool found to merge a
  keep (l)ocal, take (o)ther, or leave (u)nresolved? u
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges
  1 other heads for branch "default"
  [1]
  $ hg diff --git
  diff --git a/a b/a
  old mode 120000
  new mode 100644
  --- a/a
  +++ b/a
  @@ -1,1 +1,1 @@
  -symlink
  \ No newline at end of file
  +data


Test only 'l' change - happens rarely, except when recovering from situations
where that was what happened.

  $ hg init test2
  $ cd test2
  $ printf base > f
  $ hg ci -Aqm0
  $ echo file > f
  $ echo content >> f
  $ hg ci -qm1
  $ hg up -qr0
  $ rm f
  $ ln -s base f
  $ hg ci -qm2
  $ hg merge
  merging f
  warning: internal :merge cannot merge symlinks for f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ tellmeabout f
  f is a symlink:
  f -> base

  $ hg up -Cqr1
  $ hg merge
  merging f
  warning: internal :merge cannot merge symlinks for f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ tellmeabout f
  f is a plain file with content:
  file
  content

  $ cd ..

Test removed 'x' flag merged with change to symlink

  $ hg init test3
  $ cd test3
  $ echo f > f
  $ chmod +x f
  $ hg ci -Aqm0
  $ chmod -x f
  $ hg ci -qm1
  $ hg up -qr0
  $ rm f
  $ ln -s dangling f
  $ hg ci -qm2
  $ hg merge
  merging f
  warning: internal :merge cannot merge symlinks for f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ tellmeabout f
  f is a symlink:
  f -> dangling

  $ hg up -Cqr1
  $ hg merge
  merging f
  warning: internal :merge cannot merge symlinks for f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ tellmeabout f
  f is a plain file with content:
  f

Test removed 'x' flag merged with content change - both ways

  $ hg up -Cqr0
  $ echo change > f
  $ hg ci -qm3
  $ hg merge -r1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ tellmeabout f
  f is a plain file with content:
  change

  $ hg up -qCr1
  $ hg merge -r3
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ tellmeabout f
  f is a plain file with content:
  change

  $ cd ..

Test merge with no common ancestor:
a: just different
b: x vs -, different (cannot calculate x, cannot ask merge tool)
c: x vs -, same (cannot calculate x, merge tool is no good)
d: x vs l, different
e: x vs l, same
f: - vs l, different
g: - vs l, same
h: l vs l, different
(where same means the filelog entry is shared and there thus is an ancestor!)

  $ hg init test4
  $ cd test4
  $ echo 0 > 0
  $ hg ci -Aqm0

  $ echo 1 > a
  $ echo 1 > b
  $ chmod +x b
  $ echo x > c
  $ chmod +x c
  $ echo 1 > d
  $ chmod +x d
  $ printf x > e
  $ chmod +x e
  $ echo 1 > f
  $ printf x > g
  $ ln -s 1 h
  $ hg ci -qAm1

  $ hg up -qr0
  $ echo 2 > a
  $ echo 2 > b
  $ echo x > c
  $ ln -s 2 d
  $ ln -s x e
  $ ln -s 2 f
  $ ln -s x g
  $ ln -s 2 h
  $ hg ci -Aqm2

  $ hg merge
  merging a
  warning: cannot merge flags for b
  merging b
  warning: cannot merge flags for c
  merging d
  warning: internal :merge cannot merge symlinks for d
  warning: conflicts while merging d! (edit, then use 'hg resolve --mark')
  merging f
  warning: internal :merge cannot merge symlinks for f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  merging h
  warning: internal :merge cannot merge symlinks for h
  warning: conflicts while merging h! (edit, then use 'hg resolve --mark')
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  warning: conflicts while merging b! (edit, then use 'hg resolve --mark')
  3 files updated, 0 files merged, 0 files removed, 5 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ hg resolve -l
  U a
  U b
  U d
  U f
  U h
  $ tellmeabout a
  a is a plain file with content:
  <<<<<<< local: 0139c5610547 - test: 2
  2
  =======
  1
  >>>>>>> other: 97e29675e796  - test: 1
  $ tellmeabout b
  b is a plain file with content:
  <<<<<<< local: 0139c5610547 - test: 2
  2
  =======
  1
  >>>>>>> other: 97e29675e796  - test: 1
  $ tellmeabout c
  c is a plain file with content:
  x
  $ tellmeabout d
  d is a symlink:
  d -> 2
  $ tellmeabout e
  e is a symlink:
  e -> x
  $ tellmeabout f
  f is a symlink:
  f -> 2
  $ tellmeabout g
  g is a symlink:
  g -> x
  $ tellmeabout h
  h is a symlink:
  h -> 2

  $ hg up -Cqr1
  $ hg merge
  merging a
  warning: cannot merge flags for b
  merging b
  warning: cannot merge flags for c
  merging d
  warning: internal :merge cannot merge symlinks for d
  warning: conflicts while merging d! (edit, then use 'hg resolve --mark')
  merging f
  warning: internal :merge cannot merge symlinks for f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  merging h
  warning: internal :merge cannot merge symlinks for h
  warning: conflicts while merging h! (edit, then use 'hg resolve --mark')
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  warning: conflicts while merging b! (edit, then use 'hg resolve --mark')
  3 files updated, 0 files merged, 0 files removed, 5 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]
  $ tellmeabout a
  a is a plain file with content:
  <<<<<<< local: 97e29675e796  - test: 1
  1
  =======
  2
  >>>>>>> other: 0139c5610547 - test: 2
  $ tellmeabout b
  b is an executable file with content:
  <<<<<<< local: 97e29675e796  - test: 1
  1
  =======
  2
  >>>>>>> other: 0139c5610547 - test: 2
  $ tellmeabout c
  c is an executable file with content:
  x
  $ tellmeabout d
  d is an executable file with content:
  1
  $ tellmeabout e
  e is an executable file with content:
  x (no-eol)
  $ tellmeabout f
  f is a plain file with content:
  1
  $ tellmeabout g
  g is a plain file with content:
  x (no-eol)
  $ tellmeabout h
  h is a symlink:
  h -> 1

  $ cd ..