[PATCH 0/5] provide better error messages for @{upstream}

Hi,

this is a small patch series to provide better error messages when '@{u}' in various forms is used. Patches are really tiny, and 2-5/5 could probably be squashed together, but this way the individual changes should be more readable.

The idea is to provide as much information as possible for the user
when @{u} cannot be resolved successfully. The following cases are
distinguished:
- branch@{u} on a branch with
  * no upstream,
  * on a branch with a configured upstream, but when a branch is not
    in remote.<remote>.fetch
- branch@{u} when branch 'branch' does not exist
- @{u} without the branch name (current branch name is used)

Zbigniew Jędrzejewski-Szmek (5):
  t1507: add additional tests for @{upstream}
  Provide branch name in error message when using @{u}
  Provide better message for barnhc_wiht_tpyo@{u}
  Be more specific if upstream branch is not fetched
  i18n: mark @{upstream} error messages for translation

 sha1_name.c                   | 20 ++++++++---
 t/t1507-rev-parse-upstream.sh | 82 +++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 95 insertions(+), 7 deletions(-)