[PATCH v4 0/9] ambiguous checkout UI & checkout.defaultRemote

v4 started as a simple bug-fix for this one-part series, but since it's not going to make 2.18.0 at this point I thought I'd do some more work on it. Comments on patches below:

Ævar Arnfjörð Bjarmason (9):
  checkout tests: index should be clean after dwim checkout

Tests that would have revealed the bug in v3.

  checkout.h: wrap the arguments to unique_tracking_name()
  checkout.[ch]: move struct declaration into *.h

Boring moving code around.

  checkout.[ch]: introduce an *_INIT macro

Make checkout.h have a TRACKING_NAME_DATA_INIT for its struct.

  checkout.[ch]: change "unique" member to "num_matches"
  checkout: pass the "num_matches" up to callers
  builtin/checkout.c: use "ret" variable for return

Refactoring with no changes yet to make subsequent changes smaller.

  checkout: add advice for ambiguous "checkout <branch>"

Even if checkout.defaultRemote is off we now print advice telling the user why their "git checkout branch" didn't work.

  checkout & worktree: introduce checkout.defaultRemote

It's now called checkout.defaultRemote not checkout.implicitRemote on Junio's suggestion. On reflection that's better.

Improved tests for git-worktree (similar to the dwim checkout tests improvements earlier), and the the documentation for git-checkout & git-worktree.

I'm omitting the tbdiff because most of it's because of the new patches in this series. Better just to read them.

 Documentation/config.txt       | 26 +++++++++++++++
 Documentation/git-checkout.txt |  9 ++++++
 Documentation/git-worktree.txt |  9 ++++++
 advice.c                       |  2 ++
 advice.h                       |  1 +
 builtin/checkout.c             | 44 ++++++++++++++++++++------
 builtin/worktree.c             |  4 +--
 checkout.c                     | 37 +++++++++++++++-------
 checkout.h                     | 16 +++++++++-
 t/t2024-checkout-dwim.sh       | 58 +++++++++++++++++++++++++++++++++-
 t/t2025-worktree-add.sh        | 21 ++++++++++++
 11 files changed, 203 insertions(+), 24 deletions(-)