view tests/test-merge-types.t @ 27372:a79cba6cb206

help: add documentation for changegroup formats

There is no formal location for spec-like technical/internal docs. The
repository makes sense as such a location because spec-like
documentation should be reviewed (ruling out a wiki). mpm has also
stated that he would like this documentation to be part of the
built-in help system. So, we establish an "internals" sub-directory
to hold this class of documentation.

The format of changegroups does not appear to be documented anywhere,
even in source code. It therefore seemed like an appropriate first thing
to document.

This patch adds low-level documentation of versions 1 and 2 of the
changegroup foromat. It currently only describes the raw data format.
There is probably room to write higher-level documentation on strategies
for producing and consuming the data. We'll leave that for another day.

The added file is not yet accessible via `hg help` nor via hgweb.
Support for this will follow in subsequent patches.

#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
  $ 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]
  $ 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 ..