view tests/test-mq-qnew.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

  $ catpatch() {
  >     cat $1 | sed -e "s/^\(# Parent \).*/\1/"
  > }
  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH
  $ runtest() {
  >     hg init mq
  >     cd mq
  > 
  >     echo a > a
  >     hg ci -Ama
  > 
  >     echo '% qnew should refuse bad patch names'
  >     hg qnew series
  >     hg qnew status
  >     hg qnew guards
  >     hg qnew .
  >     hg qnew ..
  >     hg qnew .hgignore
  >     hg qnew .mqfoo
  >     hg qnew 'foo#bar'
  >     hg qnew 'foo:bar'
  >     hg qnew "`echo foo; echo bar`"
  >     hg qnew ' foo'
  >     hg qnew 'foo '
  > 
  >     hg qinit -c
  > 
  >     echo '% qnew with name containing slash'
  >     hg qnew foo/
  >     hg qnew foo/bar.patch
  >     hg qnew foo
  >     hg qseries
  >     hg qpop
  >     hg qdelete foo/bar.patch
  > 
  >     echo '% qnew with uncommitted changes'
  >     echo a > somefile
  >     hg add somefile
  >     hg qnew uncommitted.patch
  >     hg st
  >     hg qseries
  > 
  >     echo '% qnew implies add'
  >     hg -R .hg/patches st
  > 
  >     echo '% qnew missing'
  >     hg qnew missing.patch missing
  > 
  >     echo '% qnew -m'
  >     hg qnew -m 'foo bar' mtest.patch
  >     catpatch .hg/patches/mtest.patch
  > 
  >     echo '% qnew twice'
  >     hg qnew first.patch
  >     hg qnew first.patch
  > 
  >     touch ../first.patch
  >     hg qimport ../first.patch
  > 
  >     echo '% qnew -f from a subdirectory'
  >     hg qpop -a
  >     mkdir d
  >     cd d
  >     echo b > b
  >     hg ci -Am t
  >     echo b >> b
  >     hg st
  >     hg qnew -g -f p
  >     catpatch ../.hg/patches/p
  > 
  >     echo '% qnew -u with no username configured'
  >     HGUSER= hg qnew -u blue red
  >     catpatch ../.hg/patches/red
  > 
  >     echo '% qnew -e -u with no username configured'
  >     HGUSER= hg qnew -e -u chartreuse fucsia
  >     catpatch ../.hg/patches/fucsia
  > 
  >     echo '% fail when trying to import a merge'
  >     hg init merge
  >     cd merge
  >     touch a
  >     hg ci -Am null
  >     echo a >> a
  >     hg ci -m a
  >     hg up -r 0
  >     echo b >> a
  >     hg ci -m b
  >     hg merge -f 1
  >     hg resolve --mark a
  >     hg qnew -f merge
  > 
  >     cd ../../..
  >     rm -r mq
  > }

plain headers

  $ echo "[mq]" >> $HGRCPATH
  $ echo "plain=true" >> $HGRCPATH
  $ mkdir sandbox
  $ (cd sandbox ; runtest)
  adding a
  % qnew should refuse bad patch names
  abort: "series" cannot be used as the name of a patch
  abort: "status" cannot be used as the name of a patch
  abort: "guards" cannot be used as the name of a patch
  abort: "." cannot be used as the name of a patch
  abort: ".." cannot be used as the name of a patch
  abort: patch name cannot begin with ".hg"
  abort: patch name cannot begin with ".mq"
  abort: '#' cannot be used in the name of a patch
  abort: ':' cannot be used in the name of a patch
  abort: '\n' cannot be used in the name of a patch
  abort: patch name cannot begin or end with whitespace
  abort: patch name cannot begin or end with whitespace
  % qnew with name containing slash
  abort: path ends in directory separator: foo/
  abort: "foo" already exists as a directory
  foo/bar.patch
  popping foo/bar.patch
  patch queue now empty
  % qnew with uncommitted changes
  uncommitted.patch
  % qnew implies add
  A .hgignore
  A series
  A uncommitted.patch
  % qnew missing
  abort: missing: * (glob)
  % qnew -m
  foo bar
  
  % qnew twice
  abort: patch "first.patch" already exists
  abort: patch "first.patch" already exists
  % qnew -f from a subdirectory
  popping first.patch
  popping mtest.patch
  popping uncommitted.patch
  patch queue now empty
  adding d/b
  M d/b
  diff --git a/d/b b/d/b
  --- a/d/b
  +++ b/d/b
  @@ -1,1 +1,2 @@
   b
  +b
  % qnew -u with no username configured
  From: blue
  
  % qnew -e -u with no username configured
  From: chartreuse
  
  % fail when trying to import a merge
  adding a
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  created new head
  merging 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 merge --abort' to abandon
  (no more unresolved files)
  abort: cannot manage merge changesets
  $ rm -r sandbox

hg headers

  $ echo "plain=false" >> $HGRCPATH
  $ mkdir sandbox
  $ (cd sandbox ; runtest)
  adding a
  % qnew should refuse bad patch names
  abort: "series" cannot be used as the name of a patch
  abort: "status" cannot be used as the name of a patch
  abort: "guards" cannot be used as the name of a patch
  abort: "." cannot be used as the name of a patch
  abort: ".." cannot be used as the name of a patch
  abort: patch name cannot begin with ".hg"
  abort: patch name cannot begin with ".mq"
  abort: '#' cannot be used in the name of a patch
  abort: ':' cannot be used in the name of a patch
  abort: '\n' cannot be used in the name of a patch
  abort: patch name cannot begin or end with whitespace
  abort: patch name cannot begin or end with whitespace
  % qnew with name containing slash
  abort: path ends in directory separator: foo/
  abort: "foo" already exists as a directory
  foo/bar.patch
  popping foo/bar.patch
  patch queue now empty
  % qnew with uncommitted changes
  uncommitted.patch
  % qnew implies add
  A .hgignore
  A series
  A uncommitted.patch
  % qnew missing
  abort: missing: * (glob)
  % qnew -m
  # HG changeset patch
  # Parent 
  foo bar
  
  % qnew twice
  abort: patch "first.patch" already exists
  abort: patch "first.patch" already exists
  % qnew -f from a subdirectory
  popping first.patch
  popping mtest.patch
  popping uncommitted.patch
  patch queue now empty
  adding d/b
  M d/b
  # HG changeset patch
  # Parent 
  
  diff --git a/d/b b/d/b
  --- a/d/b
  +++ b/d/b
  @@ -1,1 +1,2 @@
   b
  +b
  % qnew -u with no username configured
  # HG changeset patch
  # User blue
  # Parent 
  
  % qnew -e -u with no username configured
  # HG changeset patch
  # User chartreuse
  # Parent 
  
  % fail when trying to import a merge
  adding a
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  created new head
  merging 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 merge --abort' to abandon
  (no more unresolved files)
  abort: cannot manage merge changesets
  $ rm -r sandbox

Test saving last-message.txt

  $ hg init repo
  $ cd repo

  $ cat > $TESTTMP/commitfailure.py <<EOF
  > from mercurial import error
  > def reposetup(ui, repo):
  >     class commitfailure(repo.__class__):
  >         def commit(self, *args, **kwargs):
  >             raise error.Abort('emulating unexpected abort')
  >     repo.__class__ = commitfailure
  > EOF
  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > # this failure occurs before editor invocation
  > commitfailure = $TESTTMP/commitfailure.py
  > EOF

  $ cat > $TESTTMP/editor.sh << EOF
  > echo "==== before editing"
  > cat \$1
  > echo "===="
  > echo "test saving last-message.txt" >> \$1
  > EOF

(test that editor is not invoked before transaction starting)

  $ rm -f .hg/last-message.txt
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg qnew -e patch
  abort: emulating unexpected abort
  [255]
  $ test -f .hg/last-message.txt
  [1]

(test that editor is invoked and commit message is saved into
"last-message.txt")

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > commitfailure = !
  > [hooks]
  > # this failure occurs after editor invocation
  > pretxncommit.unexpectedabort = false
  > EOF

  $ rm -f .hg/last-message.txt
  $ hg status
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg qnew -e patch
  ==== before editing
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to use default message.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: no files changed
  ====
  note: commit message saved in .hg/last-message.txt
  transaction abort!
  rollback completed
  abort: pretxncommit.unexpectedabort hook exited with status 1
  [255]
  $ cat .hg/last-message.txt
  
  
  test saving last-message.txt

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > pretxncommit.unexpectedabort =
  > EOF