tests/test-manifest-merging.t

revset: factor out getinteger() helper

We have 4 revset functions that take integer arguments, and they handle
their arguments in slightly different ways. This patch unifies them:

 - getstring() in place of getsymbol(), which is more consistent with the
   handling of integer revisions (both 1 and '1' are valid)
 - say "expects" instead of "requires" for type errors

We don't need to catch TypeError since getstring() must return a string.

  $ hg init base

  $ cd base
  $ echo 'alpha' > alpha
  $ hg ci -A -m 'add alpha'
  adding alpha
  $ cd ..

  $ hg clone base work
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd work
  $ echo 'beta' > beta
  $ hg ci -A -m 'add beta'
  adding beta
  $ cd ..

  $ cd base
  $ echo 'gamma' > gamma
  $ hg ci -A -m 'add gamma'
  adding gamma
  $ cd ..

  $ cd work
  $ hg pull -q
  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Update --clean to revision 1 to simulate a failed merge:

  $ rm alpha beta gamma
  $ hg update --clean 1
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd ..