view tests/test-hgwebdirsym.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

#require serve symlink

Tests whether or not hgwebdir properly handles various symlink topologies.

hide outer repo
  $ hg init

  $ hg init a
  $ echo a > a/a
  $ hg --cwd a ci -Ama -d'1 0'
  adding a
  $ mkdir webdir
  $ cd webdir
  $ hg init b
  $ echo b > b/b
  $ hg --cwd b ci -Amb -d'2 0'
  adding b
  $ hg init c
  $ echo c > c/c
  $ hg --cwd c ci -Amc -d'3 0'
  adding c
  $ ln -s ../a al
  $ ln -s ../webdir circle
  $ root=`pwd`
  $ cd ..
  $ cat > collections.conf <<EOF
  > [collections]
  > $root=$root
  > EOF
  $ hg serve -p $HGPORT -d --pid-file=hg.pid --webdir-conf collections.conf \
  >     -A access-collections.log -E error-collections.log
  $ cat hg.pid >> $DAEMON_PIDS

should succeed

  $ get-with-headers.py localhost:$HGPORT '?style=raw'
  200 Script output follows
  
  
  /al/
  /b/
  /c/
  
  $ get-with-headers.py localhost:$HGPORT 'al/file/tip/a?style=raw'
  200 Script output follows
  
  a
  $ get-with-headers.py localhost:$HGPORT 'b/file/tip/b?style=raw'
  200 Script output follows
  
  b
  $ get-with-headers.py localhost:$HGPORT 'c/file/tip/c?style=raw'
  200 Script output follows
  
  c

should fail

  $ get-with-headers.py localhost:$HGPORT 'circle/al/file/tip/a?style=raw'
  404 Not Found
  
  
  error: repository circle/al/file/tip/a not found
  [1]
  $ get-with-headers.py localhost:$HGPORT 'circle/b/file/tip/a?style=raw'
  404 Not Found
  
  
  error: repository circle/b/file/tip/a not found
  [1]
  $ get-with-headers.py localhost:$HGPORT 'circle/c/file/tip/a?style=raw'
  404 Not Found
  
  
  error: repository circle/c/file/tip/a not found
  [1]

collections errors

  $ cat error-collections.log