tests/test-issue1502.t

run-tests: move diff generation into TestResult

TestResult is the thing that captures all our test results. It's logical
for diff viewing to be handled there and not inside Test.

While writing this patch, it was discovered that Test.fail() was
printing redundant test result output. This has been removed.

Arguments controlling diffs have been removed from Test.__init__.

http://mercurial.selenic.com/bts/issue1502

Initialize repository

  $ hg init foo
  $ touch foo/a && hg -R foo commit -A -m "added a"
  adding a

  $ hg clone foo foo1
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ echo "bar" > foo1/a && hg -R foo1 commit -m "edit a in foo1"
  $ echo "hi" > foo/a && hg -R foo commit -m "edited a foo"
  $ hg -R foo1 pull -u
  pulling from $TESTTMP/foo (glob)
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  not updating: not a linear update
  (merge or update --check to force update)

  $ hg -R foo1 book branchy
  $ hg -R foo1 book
   * branchy                   1:e3e522925eff

Pull. Bookmark should not jump to new head.

  $ echo "there" >> foo/a && hg -R foo commit -m "edited a again"
  $ hg -R foo1 pull
  pulling from $TESTTMP/foo (glob)
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  (run 'hg update' to get a working copy)

  $ hg -R foo1 book
   * branchy                   1:e3e522925eff