view tests/test-bugzilla.t @ 36672:9e7b14caf67f

xdiff: remove patience and histogram diff algorithms

Patience diff is the normal diff algorithm, plus some greediness that
unconditionally matches common common unique lines.  That means it is easy to
construct cases to let it generate suboptimal result, like:

```
open('a', 'w').write('\n'.join(list('a' + 'x' * 300 + 'u' + 'x' * 700 + 'a\n')))
open('b', 'w').write('\n'.join(list('b' + 'x' * 700 + 'u' + 'x' * 300 + 'b\n')))
```

Patience diff has been advertised as being able to generate better results for
some C code changes. However, the more scientific way to do that is the
indention heuristic [1].

Since patience diff could generate suboptimal result more easily and its
"better" diff feature could be replaced by the new indention heuristic, let's
just remove it and its variant histogram diff to simplify the code.

[1]: https://github.com/git/git/commit/433860f3d0beb0c6f205290bd16cda413148f098

Test Plan:
`gcc -fPIC *.c --shared -o xdiff.so` still builds.

Differential Revision: https://phab.mercurial-scm.org/D2573

mock bugzilla driver for testing template output:

  $ cat <<EOF > bzmock.py
  > from __future__ import absolute_import
  > from mercurial import extensions
  > from mercurial import registrar
  > 
  > configtable = {}
  > configitem = registrar.configitem(configtable)
  > 
  > configitem('bugzilla', 'mocklog',
  >     default=None,
  > )
  > def extsetup(ui):
  >     bugzilla = extensions.find('bugzilla')
  >     class bzmock(bugzilla.bzaccess):
  >         def __init__(self, ui):
  >             super(bzmock, self).__init__(ui)
  >             self._logfile = ui.config('bugzilla', 'mocklog')
  >         def updatebug(self, bugid, newstate, text, committer):
  >             with open(self._logfile, 'a') as f:
  >                 f.write('update bugid=%r, newstate=%r, committer=%r\n'
  >                         % (bugid, newstate, committer))
  >                 f.write('----\n' + text + '\n----\n')
  >         def notify(self, bugs, committer):
  >             with open(self._logfile, 'a') as f:
  >                 f.write('notify bugs=%r, committer=%r\n'
  >                         % (bugs, committer))
  >     bugzilla.bugzilla._versions['mock'] = bzmock
  > EOF

set up mock repository:

  $ hg init mockremote
  $ cat <<EOF > mockremote/.hg/hgrc
  > [extensions]
  > bugzilla =
  > bzmock = $TESTTMP/bzmock.py
  > 
  > [bugzilla]
  > version = mock
  > mocklog = $TESTTMP/bzmock.log
  > 
  > [hooks]
  > incoming.bugzilla = python:hgext.bugzilla.hook
  > 
  > [web]
  > baseurl=http://example.org/hg
  > 
  > %include $TESTTMP/bzstyle.hgrc
  > EOF

  $ hg clone -q mockremote mocklocal

push with default template:

  $ echo '[bugzilla]' > bzstyle.hgrc
  $ echo foo > mocklocal/foo
  $ hg ci -R mocklocal -Aqm 'Fixes bug 123'
  $ hg -R mocklocal push -q
  $ cat bzmock.log && rm bzmock.log
  update bugid=123, newstate={}, committer='test'
  ----
  changeset 7875a8342c6f in repo $TESTTMP/mockremote refers to bug 123.
  details:
  	Fixes bug 123
  ----
  notify bugs={123: {}}, committer='test'

push with style:

  $ cat <<EOF > bzstyle.map
  > changeset = "{node|short} refers to bug {bug}."
  > EOF
  $ echo "style = $TESTTMP/bzstyle.map" >> bzstyle.hgrc
  $ echo foo >> mocklocal/foo
  $ hg ci -R mocklocal -qm 'Fixes bug 456'
  $ hg -R mocklocal push -q
  $ cat bzmock.log && rm bzmock.log
  update bugid=456, newstate={}, committer='test'
  ----
  2808b172464b refers to bug 456.
  ----
  notify bugs={456: {}}, committer='test'

push with template (overrides style):

  $ cat <<EOF >> bzstyle.hgrc
  > template = Changeset {node|short} in {root|basename}.
  >            {hgweb}/rev/{node|short}\n
  >            {desc}
  > EOF
  $ echo foo >> mocklocal/foo
  $ hg ci -R mocklocal -qm 'Fixes bug 789'
  $ hg -R mocklocal push -q
  $ cat bzmock.log && rm bzmock.log
  update bugid=789, newstate={}, committer='test'
  ----
  Changeset a770f3e409f2 in mockremote.
  http://example.org/hg/rev/a770f3e409f2
  
  Fixes bug 789
  ----
  notify bugs={789: {}}, committer='test'