tests/test-paths.t

discovery: drop findoutgoing and simplify findcommonincoming's api

This is a long desired cleanup and paves the way for new discovery.
To specify subsets for bundling changes, all code should use the heads
of the desired subset ("heads") and the heads of the common subset
("common") to be excluded from the bundled set. These can be used
revlog.findmissing instead of revlog.nodesbetween.

This fixes an actual bug exposed by the change in test-bundle-r.t
where we try to bundle a changeset while specifying that said changeset
is to be assumed already present in the target. This used to still
bundle the changeset. It no longer does. This is similar to the bugs
fixed by the recent switch to heads/common for incoming/pull.

  $ hg init a
  $ hg clone a b
  updating to branch default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd a
  $ echo '[paths]' >> .hg/hgrc
  $ echo 'dupe = ../b' >> .hg/hgrc
  $ echo 'expand = $SOMETHING/bar' >> .hg/hgrc
  $ hg in dupe
  comparing with $TESTTMP/b
  no changes found
  [1]
  $ cd ..
  $ hg -R a in dupe
  comparing with $TESTTMP/b
  no changes found
  [1]
  $ cd a
  $ hg paths
  dupe = $TESTTMP/b
  expand = $TESTTMP/a/$SOMETHING/bar
  $ SOMETHING=foo hg paths
  dupe = $TESTTMP/b
  expand = $TESTTMP/a/foo/bar
  $ SOMETHING=/foo hg paths
  dupe = $TESTTMP/b
  expand = /foo/bar
  $ cd ..

'file:' disables [paths] entries for clone destination

  $ cat >> $HGRCPATH <<EOF
  > [paths]
  > gpath1 = http://hg.example.com
  > EOF

  $ hg clone a gpath1
  abort: cannot create new http repository
  [255]

  $ hg clone a file:gpath1
  updating to branch default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd gpath1
  $ hg -q id
  000000000000