zsh_completion: use revsets to exclude this rev from suggestions to hg merge One of the most important aspects of a completion system is its speed, so 1 call to hg is definitely better than 4. Sorting by rev (descending) is to preserve the same order as in `hg heads` output. While at it, declare branches as an array too. Differential Revision: https://phab.mercurial-scm.org/D4426

  $ hg init
  $ echo This is file a1 > a
  $ hg add a
  $ hg commit -m "commit #0"
  $ ls
  a
  $ echo This is file b1 > b
  $ hg add b
  $ hg commit -m "commit #1"
  $ hg co 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

B should disappear

  $ ls
  a