Re: [PATCH v7 8/8] branch: protect branches checked out in all worktrees

Refuse to force-move a branch over the currently checked out branch of
any working tree, not just the current one.

Signed-off-by: Anders Kaseorg <redacted>
---
 branch.c          | 13 +++++++++----
 t/t3200-branch.sh |  7 +++++++
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/branch.c b/branch.c
index c66b222abd..2cfe496d24 100644
--- a/branch.c
+++ b/branch.c

@@ -199,7 +199,8 @@ int validate_branchname(const char *name, struct strbuf *ref)
  */
 int validate_new_branchname(const char *name, struct strbuf *ref, int force)
 {
-       const char *head;
+       struct worktree **worktrees;
+       const struct worktree *wt;

        if (!validate_branchname(name, ref))
                return 0;

@@ -208,9 +209,13 @@ int validate_new_branchname(const char *name, struct strbuf *ref, int force)
                die(_("a branch named '%s' already exists"),
                    ref->buf + strlen("refs/heads/"));

-       head = resolve_ref_unsafe("HEAD", 0, NULL, NULL);
-       if (!is_bare_repository() && head && !strcmp(head, ref->buf))
-               die(_("cannot force update the current branch"));
+       worktrees = get_worktrees();
+       wt = find_shared_symref(worktrees, "HEAD", ref->buf);
+       if (wt && !wt->is_bare)
+               die(_("cannot force update the branch '%s'"
+                     "checked out at '%s'"),