tests/test-issue1877.t

graphlog: remove useless check for empty repo when --follow is specified

This prepares for extracting common part from getgraphlogrevs() and
getlogrevs(). getlogrevs() does not handle empty repo specially.

When it was added at d74099ac2ac1, revs were build by old-style query, '.:0'.
So I think the purpose of "len(repo) > 0" was to handle the case of . = null.
Currently it isn't necessary for 'reverse(:.)', and it does not work if repo
is not empty but p1 is null.

  $ hg up null
  $ hg glog --follow -T '{rev}:{node|short}\n'
  o  0:0a04b987be5a

The subsequent patch will fix this problem, so drops the wrong version for now.

http://mercurial.selenic.com/bts/issue1877

  $ hg init a
  $ cd a
  $ echo a > a
  $ hg add a
  $ hg ci -m 'a'
  $ echo b > a
  $ hg ci -m'b'
  $ hg up 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg book main
  $ hg book
   * main                      0:cb9a9f314b8b
  $ echo c > c
  $ hg add c
  $ hg ci -m'c'
  created new head
  $ hg book
   * main                      2:d36c0562f908
  $ hg heads
  changeset:   2:d36c0562f908
  bookmark:    main
  tag:         tip
  parent:      0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     c
  
  changeset:   1:1e6c11564562
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     b
  
  $ hg up 1e6c11564562
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (leaving bookmark main)
  $ hg merge main
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg book
     main                      2:d36c0562f908
  $ hg ci -m'merge'
  $ hg book
     main                      2:d36c0562f908

  $ cd ..