tests/test-merge-types.t

posix: add extended support for OS X path folding

OS X does the following transformation on paths for comparisons:

a) 8-bit strings are decoded as UTF-8 to UTF-16
b) undecodable bytes are percent-escaped
c) accented characters are converted to NFD decomposed form, approximately
d) characters are converted to _lowercase_ using internal tables

Both (c) and (d) are done using internal tables that vary from release
to release and match Unicode specs to greater or lesser extent. We
approximate these functions using Python's internal Unicode data.

With this change, Mercurial will (in almost all cases) match OS X
folding and not report unknown file aliases for files in UTF-8 or
other encodings.

  $ hg init

  $ echo a > a
  $ hg ci -Amadd
  adding a

  $ chmod +x a
  $ hg ci -mexecutable

  $ hg up 0
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm a
  $ ln -s symlink a
  $ hg ci -msymlink
  created new head

  $ hg merge --debug
    searching for copies back to rev 1
  resolving manifests
   overwrite None partial False
   ancestor c334dc3be0da local 521a1e40188f+ remote 3574f3e69b1c
   conflicting flags for a
  (n)one, e(x)ec or sym(l)ink? n
   a: update permissions -> e
  updating: a 1/1 files (100.00%)
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)


Symlink is local parent, executable is other:

  $ if [ -h a ]; then
  >     echo a is a symlink
  >     $TESTDIR/readlink.py a
  > elif [ -x a ]; then
  >     echo a is executable
  > else
  >     echo "a has no flags (default for conflicts)"
  > fi
  a has no flags (default for conflicts)

  $ hg update -C 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg merge --debug
    searching for copies back to rev 1
  resolving manifests
   overwrite None partial False
   ancestor c334dc3be0da local 3574f3e69b1c+ remote 521a1e40188f
   conflicting flags for a
  (n)one, e(x)ec or sym(l)ink? n
   a: remote is newer -> g
  updating: a 1/1 files (100.00%)
  getting a
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)


Symlink is other parent, executable is local:

  $ if [ -h a ]; then
  >    echo a is a symlink
  >    $TESTDIR/readlink.py a
  > elif [ -x a ]; then
  >     echo a is executable
  > else
  >     echo "a has no flags (default for conflicts)"
  > fi
  a has no flags (default for conflicts)