tests/test-issue2137.t

ui: move URL and path detection into path API

ui.expandpath() has code for recognizing URLs or local filesystem
paths. Our goal is to use ``path`` class instances everywhere a path
is represented.

Changing ui.expandpath() to return path instances is a lot of work.
Our goal is to slowly marginalize it by moving logic into the paths
API and to convert callers to the paths API.

Many callers of ui.expandpath() pass in a value that could be a
local filesystem path or URI. We move the detection of these strings
from ui.expandpath() to paths.getpath() and path.__init__(). To do
this properly in a way that is compatible with future callers, we
need to parse the "#branch" syntax out of locations. This is a bit
complicated, but it is necessary.

The code for URL parsing is essentially a copy of hg.parseurl().
Once all consumers are speaking the paths API, it is likely that
this function won't be called any more and it can be deleted.

http://mercurial.selenic.com/bts/issue2137

Setup:

create a little extension that has 3 side-effects:
1) ensure changelog data is not inlined
2) make revlog to use lazyparser
3) test that repo.lookup() works
1 and 2 are preconditions for the bug; 3 is the bug.

  $ cat > commitwrapper.py <<EOF
  > from mercurial import extensions, node, revlog
  > 
  > def reposetup(ui, repo):
  >     class wraprepo(repo.__class__):
  >         def commit(self, *args, **kwargs):
  >             result = super(wraprepo, self).commit(*args, **kwargs)
  >             tip1 = node.short(repo.changelog.tip())
  >             tip2 = node.short(repo.lookup(tip1))
  >             assert tip1 == tip2
  >             ui.write('new tip: %s\n' % tip1)
  >             return result
  >     repo.__class__ = wraprepo
  > 
  > def extsetup(ui):
  >     revlog._maxinline = 8             # split out 00changelog.d early
  >     revlog._prereadsize = 8           # use revlog.lazyparser
  > EOF

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > commitwrapper = `pwd`/commitwrapper.py
  > EOF

  $ hg init repo1
  $ cd repo1
  $ echo a > a
  $ hg commit -A -m'add a with a long commit message to make the changelog a bit bigger'
  adding a
  new tip: 553596fad57b

Test that new changesets are visible to repo.lookup():

  $ echo a >> a
  $ hg commit -m'one more commit to demonstrate the bug'
  new tip: 799ae3599e0e

  $ hg tip
  changeset:   1:799ae3599e0e
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     one more commit to demonstrate the bug
  

  $ cd ..