Merge branch 'es/do-not-let-rebase-switch-to-protected-branch'

"git rebase BASE BRANCH" rebased/updated the tip of BRANCH and
checked it out, even when the BRANCH is checked out in a different
worktree.  This has been corrected.

* es/do-not-let-rebase-switch-to-protected-branch:
  rebase: refuse to switch to branch already checked out elsewhere
  t3400: make test clean up after itself

builtin/rebase.c

@@ -2044,10 +2044,11 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		/* Is it a local branch? */
 		strbuf_reset(&buf);
 		strbuf_addf(&buf, "refs/heads/%s", branch_name);
-		if (!read_ref(buf.buf, &options.orig_head))
+		if (!read_ref(buf.buf, &options.orig_head)) {
+			die_if_checked_out(buf.buf, 1);
 			options.head_name = xstrdup(buf.buf);
 		/* If not is it a valid ref (branch or commit)? */
-		else if (!get_oid(branch_name, &options.orig_head))
+		} else if (!get_oid(branch_name, &options.orig_head))
 			options.head_name = NULL;
 		else
 			die(_("fatal: no such branch/commit '%s'"),

t/t3400-rebase.sh

@@ -143,11 +143,11 @@ test_expect_success 'setup: recover' '
 
 test_expect_success 'Show verbose error when HEAD could not be detached' '
 	>B &&
+	test_when_finished "rm -f B" &&
 	test_must_fail git rebase topic 2>output.err >output.out &&
 	test_i18ngrep "The following untracked working tree files would be overwritten by checkout:" output.err &&
 	test_i18ngrep B output.err
 '
-rm -f B
 
 test_expect_success 'fail when upstream arg is missing and not on branch' '
 	git checkout topic &&
@@ -401,4 +401,22 @@ test_expect_success 'rebase -c rebase.useBuiltin=false warning' '
 	test_must_be_empty err
 '
 
+test_expect_success 'switch to branch checked out here' '
+	git checkout master &&
+	git rebase master master
+'
+
+test_expect_success 'switch to branch not checked out' '
+	git checkout master &&
+	git branch other &&
+	git rebase master other
+'
+
+test_expect_success 'refuse to switch to branch checked out elsewhere' '
+	git checkout master &&
+	git worktree add wt &&
+	test_must_fail git -C wt rebase master master 2>err &&
+	test_i18ngrep "already checked out" err
+'
+
 test_done