view tests/test-histedit-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 histedit command

Setup

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > histedit=
  > [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 histedit -Tjson --commands - 2>&1 <<EOF
  > pick 28ad74487de9 Added c
  > pick 62615734edd5 Added d
  > pick 18d04c59bb5d Added a
  > pick 29becc82797a Added b
  > EOF
  [
   {
    "nodechanges": {"18d04c59bb5d2d4090ad9a5b59bd6274adb63add": ["109f8ec895447f81b380ba8d4d8b66539ccdcb94"], "28ad74487de9599d00d81085be739c61fc340652": ["bff9e07c1807942b161dab768aa793b48e9a7f9d"], "29becc82797a4bc11ec8880b58eaecd2ab3e7760": ["f5dcf3b4db23f31f1aacf46c33d1393de303d26f"], "62615734edd52f06b6fb9c2beb429e4fe30d57b8": ["201423b441c84d9e6858daed653e0d22485c1cfa"]}
   }
  ]

  $ hg log -G -T "{rev}:{node|short} {desc}"
  @  7:f5dcf3b4db23 Added b
  |
  o  6:109f8ec89544 Added a
  |
  o  5:201423b441c8 Added d
  |
  o  4:bff9e07c1807 Added c
  
  $ hg histedit -T "{nodechanges|json}" --commands - 2>&1 <<EOF
  > pick bff9e07c1807 Added c
  > pick 201423b441c8 Added d
  > pick 109f8ec89544 Added a
  > roll f5dcf3b4db23 Added b
  > EOF
  {"109f8ec895447f81b380ba8d4d8b66539ccdcb94": ["8d01470bfeab64d3de13c49adb79d88790d38396"], "f3ec56a374bdbdf1953cacca505161442c6f3a3e": [], "f5dcf3b4db23f31f1aacf46c33d1393de303d26f": ["8d01470bfeab64d3de13c49adb79d88790d38396"]} (no-eol)