tests/test-push-validation.t

rebase: improve error message on improper phases

The previous error message had two issues: The first issue was that it
wasn't, in fact, an error but a warning, even though it described a
fatal error condition preventing the successful completion of the
command. The second was that it didn't mention the immutable
changesets, leaving the user guessing at the true cause of the error.

The main downside to this change is that we now get an 'abort: can't
abort...' message which technically contradicts itself. In this case,
I blame that on the two uses we have for the word; if it weren't for
backwards compatibility, we could make util.Abort print out 'error:
<whatever>'.

  $ hg init test
  $ cd test

  $ cat > .hg/hgrc <<EOF
  > [server]
  > validate=1
  > EOF

  $ echo alpha > alpha
  $ echo beta > beta
  $ hg addr
  adding alpha
  adding beta
  $ hg ci -m 1

  $ cd ..
  $ hg clone test test-clone
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd test-clone
  $ cp .hg/store/data/beta.i tmp
  $ echo blah >> beta
  $ hg ci -m '2 (corrupt)'
  $ mv tmp .hg/store/data/beta.i

Expected to fail:

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
   beta@1: dddc47b3ba30 in manifests not found
  2 files, 2 changesets, 2 total revisions
  1 integrity errors encountered!
  (first damaged changeset appears to be 1)
  [1]

Expected to fail:

  $ hg push
  pushing to $TESTTMP/test (glob)
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  transaction abort!
  rollback completed
  abort: missing file data for beta:dddc47b3ba30e54484720ce0f4f768a0f4b6efb9 - run hg verify
  [255]