Merge branch 'rj/branch-unborn-in-other-worktrees' into seen

* rj/branch-unborn-in-other-worktrees:
  branch: rename orphan branches in any worktree
  branch: description for orphan branch errors
  avoid unnecessary worktrees traversing

Author: gitster

builtin/branch.c

@@ -486,14 +486,17 @@ static void print_current_branch_name(void)
 		die(_("HEAD (%s) points outside of refs/heads/"), refname);
 }
 
-static void reject_rebase_or_bisect_branch(const char *target)
+static int ishead_and_reject_rebase_or_bisect_branch(const char *target)
 {
 	struct worktree **worktrees = get_worktrees();
-	int i;
+	int i, ret = 0;
 
 	for (i = 0; worktrees[i]; i++) {
 		struct worktree *wt = worktrees[i];
 
+		if (wt->head_ref && !strcmp(target, wt->head_ref))
+			ret = 1 + (is_null_oid(&wt->head_oid) ? 1 : 0);
+
 		if (!wt->is_detached)
 			continue;
 
@@ -507,6 +510,7 @@ static void reject_rebase_or_bisect_branch(const char *target)
 	}
 
 	free_worktrees(worktrees);
+	return ret;
 }
 
 static void copy_or_rename_branch(const char *oldname, const char *newname, int copy, int force)
@@ -515,7 +519,7 @@ static void copy_or_rename_branch(const char *oldname, const char *newname, int
 	struct strbuf oldsection = STRBUF_INIT, newsection = STRBUF_INIT;
 	const char *interpreted_oldname = NULL;
 	const char *interpreted_newname = NULL;
-	int recovery = 0;
+	int recovery = 0, ishead;
 
 	if (strbuf_check_branch_ref(&oldref, oldname)) {
 		/*
@@ -528,12 +532,12 @@ static void copy_or_rename_branch(const char *oldname, const char *newname, int
 			die(_("Invalid branch name: '%s'"), oldname);
 	}
 
-	if ((copy || strcmp(head, oldname)) && !ref_exists(oldref.buf)) {
-		if (copy && !strcmp(head, oldname))
-			die(_("No commit on branch '%s' yet."), oldname);
-		else
-			die(_("No branch named '%s'."), oldname);
-	}
+	ishead = ishead_and_reject_rebase_or_bisect_branch(oldref.buf);
+
+	if ((copy || !ishead) && !ref_exists(oldref.buf))
+		die(ishead
+		    ? _("No commit on branch '%s' yet.")
+		    : _("No branch named '%s'."), oldname);
 
 	/*
 	 * A command like "git branch -M currentbranch currentbranch" cannot
@@ -544,8 +548,6 @@ static void copy_or_rename_branch(const char *oldname, const char *newname, int
 	else
 		validate_new_branchname(newname, &newref, force);
 
-	reject_rebase_or_bisect_branch(oldref.buf);
-
 	if (!skip_prefix(oldref.buf, "refs/heads/", &interpreted_oldname) ||
 	    !skip_prefix(newref.buf, "refs/heads/", &interpreted_newname)) {
 		BUG("expected prefix missing for refs");
@@ -558,8 +560,7 @@ static void copy_or_rename_branch(const char *oldname, const char *newname, int
 		strbuf_addf(&logmsg, "Branch: renamed %s to %s",
 			    oldref.buf, newref.buf);
 
-	if (!copy &&
-	    (!head || strcmp(oldname, head) || !is_null_oid(&head_oid)) &&
+	if (!copy && !(ishead > 1) &&
 	    rename_ref(oldref.buf, newref.buf, logmsg.buf))
 		die(_("Branch rename failed"));
 	if (copy && copy_existing_ref(oldref.buf, newref.buf, logmsg.buf))
@@ -574,7 +575,7 @@ static void copy_or_rename_branch(const char *oldname, const char *newname, int
 				interpreted_oldname);
 	}
 
-	if (!copy &&
+	if (!copy && ishead &&
 	    replace_each_worktree_head_symref(oldref.buf, newref.buf, logmsg.buf))
 		die(_("Branch renamed to %s, but HEAD is not updated!"), newname);
 
@@ -806,7 +807,7 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 
 		strbuf_addf(&branch_ref, "refs/heads/%s", branch_name);
 		if (!ref_exists(branch_ref.buf))
-			error((!argc || !strcmp(head, branch_name))
+			error((!argc || branch_checked_out(branch_ref.buf))
 			      ? _("No commit on branch '%s' yet.")
 			      : _("No branch named '%s'."),
 			      branch_name);
@@ -850,11 +851,10 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 			die(_("no such branch '%s'"), argv[0]);
 		}
 
-		if (!ref_exists(branch->refname)) {
-			if (!argc || !strcmp(head, branch->name))
-				die(_("No commit on branch '%s' yet."), branch->name);
-			die(_("branch '%s' does not exist"), branch->name);
-		}
+		if (!ref_exists(branch->refname))
+			die((!argc || branch_checked_out(branch->refname))
+			    ? _("No commit on branch '%s' yet.")
+			    : _("branch '%s' does not exist"), branch->name);
 
 		dwim_and_setup_tracking(the_repository, branch->name,
 					new_upstream, BRANCH_TRACK_OVERRIDE,

t/t3200-branch.sh

@@ -280,6 +280,22 @@ test_expect_success 'git branch -M and -C fail on detached HEAD' '
 	test_cmp expect err
 '
 
+test_expect_success 'git branch -m should work with orphan branches' '
+	test_when_finished git checkout - &&
+	test_when_finished git worktree remove -f wt &&
+	git worktree add wt --detach &&
+
+	# rename orphan in another worktreee
+	git -C wt checkout --orphan orphan-foo-wt &&
+	git branch -m orphan-foo-wt orphan-bar-wt &&
+	test orphan-bar-wt=$(git -C orphan-worktree branch --show-current) &&
+
+	# rename orphan in the current worktree
+	git checkout --orphan orphan-foo &&
+	git branch -m orphan-foo orphan-bar &&
+	test orphan-bar=$(git branch --show-current)
+'
+
 test_expect_success 'git branch -d on orphan HEAD (merged)' '
 	test_when_finished git checkout main &&
 	git checkout --orphan orphan &&

t/t3202-show-branch.sh

@@ -221,4 +221,22 @@ test_expect_success 'fatal descriptions on non-existent branch' '
 	test_cmp expect actual
 '
 
+test_expect_success 'error descriptions on orphan branch' '
+	test_when_finished git worktree remove -f wt &&
+	git worktree add wt --detach &&
+	git -C wt checkout --orphan orphan-branch &&
+	test_branch_op_in_wt() {
+		test_orphan_error() {
+			test_must_fail git $* 2>actual &&
+			test_i18ngrep "No commit on branch .orphan-branch. yet.$" actual
+		} &&
+		test_orphan_error -C wt branch $1 $2 &&                # implicit branch
+		test_orphan_error -C wt branch $1 orphan-branch $2 &&  # explicit branch
+		test_orphan_error branch $1 orphan-branch $2           # different worktree
+	} &&
+	test_branch_op_in_wt --edit-description &&
+	test_branch_op_in_wt --set-upstream-to=ne &&
+	test_branch_op_in_wt -c new-branch
+'
+
 test_done