[PATCH 0/3] Testing: XDG config files: Fix broken tests

The tests for the new XDG config file code are broken because the environoment variable `XDG_CONFIG_HOME' is never set properly, and the tests themselves do not use `XDG_CONFIG_HOME' or `HOME' explicitly.

The following patch series corrects this brittleness (and the failures to which it has led):

  t/t1306-xdg-files.sh | 69 +++++++++++++++++++++++++++-------------------------
  t/test-lib.sh        |  3 +++
  2 files changed, 39 insertions(+), 33 deletions(-)

  [1] Export a suitable `XDG_CONFIG_HOME' environment variable
  [2] Use "$HOME" and "$XDG_CONFIG_HOME" explicitly
  [3] Trivial: `xdg' -> `XDG'