tests/test-merge4.t

template: fix shortest(node) function in pure mercurial

Pure mercurial (i.e. without c extensions) does not support partialmatch() on
the revlog index, so we must fall back to use revlog._partialmatch() to handle
that case for us. The tests caught this.

We don't use revlog._partialmatch() for the normal case because it performs a
very expensive index iteration when the string being tested fails to find a
unique result via index.partialmatch(). It does this in order to filter
out hidden revs in hopes of the string being unique amongst non-hidden revs.
For the shortest(node) case, we'd prefer performance over worrying about
hidden revs.

  $ hg init
  $ echo This is file a1 > a
  $ hg add a
  $ hg commit -m "commit #0"
  $ echo This is file b1 > b
  $ hg add b
  $ hg commit -m "commit #1"
  $ hg update 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo This is file c1 > c
  $ hg add c
  $ hg commit -m "commit #2"
  created new head
  $ hg merge 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ rm b
  $ echo This is file c22 > c

Test hg behaves when committing with a missing file added by a merge

  $ hg commit -m "commit #3"
  abort: cannot commit merge with missing files
  [255]