view tests/test-rebase-templates.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

Testing templating for rebase command

Setup

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > [experimental]
  > evolution=createmarkers
  > EOF

  $ hg init repo
  $ cd repo
  $ for ch in a b c d; do echo foo > $ch; hg commit -Aqm "Added "$ch; done

  $ hg log -G -T "{rev}:{node|short} {desc}"
  @  3:62615734edd5 Added d
  |
  o  2:28ad74487de9 Added c
  |
  o  1:29becc82797a Added b
  |
  o  0:18d04c59bb5d Added a
  
Getting the JSON output for nodechanges

  $ hg rebase -s 2 -d 0 -q -Tjson
  [
   {
    "nodechanges": {"28ad74487de9599d00d81085be739c61fc340652": ["849767420fd5519cf0026232411a943ed03cc9fb"], "62615734edd52f06b6fb9c2beb429e4fe30d57b8": ["df21b32134ba85d86bca590cbe9b8b7cbc346c53"]}
   }
  ]

  $ hg log -G -T "{rev}:{node|short} {desc}"
  @  5:df21b32134ba Added d
  |
  o  4:849767420fd5 Added c
  |
  | o  1:29becc82797a Added b
  |/
  o  0:18d04c59bb5d Added a
  
  $ hg rebase -s 1 -d 5 -q -T "{nodechanges|json}"
  {"29becc82797a4bc11ec8880b58eaecd2ab3e7760": ["d9d6773efc831c274eace04bc13e8e6412517139"]} (no-eol)

  $ hg log -G -T "{rev}:{node|short} {desc}"
  o  6:d9d6773efc83 Added b
  |
  @  5:df21b32134ba Added d
  |
  o  4:849767420fd5 Added c
  |
  o  0:18d04c59bb5d Added a
  

  $ hg rebase -s 6 -d 4 -q -T "{nodechanges % '{oldnode}:{newnodes % ' {node} '}'}"
  d9d6773efc831c274eace04bc13e8e6412517139: f48cd65c6dc3d2acb55da54402a5b029546e546f  (no-eol)