[PATCH v6 0/8] protect branches checked out in all worktrees

‘git fetch’ (without ‘--update-head-ok’), ‘git receive-pack’, and ‘git branch -M’ protect the currently checked out branch from being accidentally updated. However, the code for these checks predates ‘git worktree’. Improve it to protect branches checked out in all worktrees, not just the current one.

Anders Kaseorg (8):
  fetch: lowercase error messages
  receive-pack: lowercase error messages
  branch: lowercase error messages
  worktree: simplify find_shared_symref() memory ownership model
  fetch: protect branches checked out in all worktrees
  receive-pack: clean dead code from update_worktree()
  receive-pack: protect current branch for bare repository worktree
  branch: protect branches checked out in all worktrees

 branch.c                        |  41 +++++++-----
 builtin/branch.c                |   7 +-
 builtin/fetch.c                 | 115 +++++++++++++++++---------------
 builtin/notes.c                 |   6 +-
 builtin/receive-pack.c          |  88 +++++++++++++-----------
 t/t2018-checkout-branch.sh      |   2 +-
 t/t3200-branch.sh               |   9 ++-
 t/t5504-fetch-receive-strict.sh |   2 +-
 t/t5516-fetch-push.sh           |  32 +++++++++
 worktree.c                      |   8 +--
 worktree.h                      |   5 +-
 11 files changed, 191 insertions(+), 124 deletions(-)