tests/test-hgk.t

subrepo: use code from 71ea5b2b9517 only if Python needs it (issue2795)

With Python >= 2.6 the original code already works correct, therefore the
fix for issue2556 on Python <= 2.5 broke relative subrepositories with
newer versions of Python.

Minimal hgk check

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "hgk=" >> $HGRCPATH
  $ hg init repo
  $ cd repo
  $ echo a > a
  $ hg ci -Am adda
  adding a
  $ hg debug-cat-file commit 0
  tree a0c8bcbbb45c
  parent 000000000000
  author test 0 0
  committer test 0 0
  revision 0
  branch default
  
  adda