commit - f2db9c479fbdf8dfb2f58619e6e62781117a14b8
commit + 45cd4e47a6fe68f4dbd45961973ed61e766bfbca
blob - 77942a84ae2f6687f4c1b016ab97b7fcc7578feb
blob + 7daf89ca750b37c1fa8b20970c7cf973af3347d7
--- got/got.c
+++ got/got.c
@@ -3104,10 +3104,11 @@ list_branches(struct got_repository *repo, struct got_
 }
 
 static const struct got_error *
-delete_branch(struct got_repository *repo, const char *branch_name)
+delete_branch(struct got_repository *repo, struct got_worktree *worktree,
+    const char *branch_name)
 {
 	const struct got_error *err = NULL;
-	struct got_reference *ref;
+	struct got_reference *ref = NULL;
 	char *refname;
 
 	if (asprintf(&refname, "refs/heads/%s", branch_name) == -1)
@@ -3117,9 +3118,18 @@ delete_branch(struct got_repository *repo, const char 
 	if (err)
 		goto done;
 
-	err = got_ref_delete(ref, repo);
-	got_ref_close(ref);
+	if (worktree &&
+	    strcmp(got_worktree_get_head_ref_name(worktree),
+	    got_ref_get_name(ref)) == 0) {
+		err = got_error_msg(GOT_ERR_SAME_BRANCH,
+		    "will not delete this work tree's current branch");
+		goto done;
+	}
+
+	err = got_ref_delete(ref, repo);
 done:
+	if (ref)
+		got_ref_close(ref);
 	free(refname);
 	return err;
 }
@@ -3276,7 +3286,7 @@ cmd_branch(int argc, char *argv[])
 	if (do_list)
 		error = list_branches(repo, worktree);
 	else if (delref)
-		error = delete_branch(repo, delref);
+		error = delete_branch(repo, worktree, delref);
 	else {
 		const char *base_branch;
 		if (argc == 1) {
blob - e624d53380913d538422ddc4c6503cb48bdf3b02
blob + a2f5c358ddb24b6a373b03188398b95b8b3d8b8c
--- regress/cmdline/branch.sh
+++ regress/cmdline/branch.sh
@@ -249,7 +249,32 @@ function test_branch_delete {
 	test_done "$testroot" "$ret"
 }
 
+function test_branch_delete_current_branch {
+	local testroot=`test_init branch_delete_current_branch`
+	local commit_id=`git_show_head $testroot/repo`
+
+	got checkout $testroot/repo $testroot/wt >/dev/null
+	ret="$?"
+	if [ "$ret" != "0" ]; then
+		echo "got checkout command failed unexpectedly"
+		test_done "$testroot" "$ret"
+		return 1
+	fi
 
+	(cd $testroot/wt && got branch -d master > $testroot/stdout \
+		2> $testroot/stderr)
+
+	echo "got: will not delete this work tree's current branch" \
+		> $testroot/stderr.expected
+	cmp -s $testroot/stderr $testroot/stderr.expected
+	ret="$?"
+	if [ "$ret" != "0" ]; then
+		diff -u $testroot/stderr.expected $testroot/stderr
+	fi
+	test_done "$testroot" "$ret"
+}
+
 run_test test_branch_create
 run_test test_branch_list
 run_test test_branch_delete
+run_test test_branch_delete_current_branch