[bugfix]json_length() BE crash fix

be/src/vec/functions/function_jsonb.cpp

@@ -1080,7 +1080,8 @@ struct JsonbLengthUtil {
         MutableColumnPtr res = return_type->create_column();
 
         for (size_t i = 0; i < input_rows_count; ++i) {
-            if (jsonb_data_column->is_null_at(i) || path_column->is_null_at(i)) {
+            if (jsonb_data_column->is_null_at(i) || path_column->is_null_at(i) ||
+                (jsonb_data_column->get_data_at(i).size == 0)) {
                 null_map->get_data()[i] = 1;
                 res->insert_data(nullptr, 0);
                 continue;
@@ -1100,7 +1101,7 @@ struct JsonbLengthUtil {
             // doc is NOT necessary to be deleted since JsonbDocument will not allocate memory
             JsonbDocument* doc = JsonbDocument::createDocument(jsonb_value.data, jsonb_value.size);
             JsonbValue* value = doc->getValue()->findValue(path, nullptr);
-            if (UNLIKELY(jsonb_value.size == 0 || !value)) {
+            if (UNLIKELY(!value)) {
                 null_map->get_data()[i] = 1;
                 res->insert_data(nullptr, 0);
                 continue;

regression-test/data/jsonb_p0/test_jsonb_load_and_function.out

@@ -7494,6 +7494,9 @@ false
 -- !sql_json_length --
 2
 
+-- !sql_json_length --
+\N
+
 -- !select_length --
 1	\N	\N
 2	null	1

regression-test/suites/jsonb_p0/test_jsonb_load_and_function.groovy

@@ -552,6 +552,7 @@ suite("test_jsonb_load_and_function", "p0") {
     qt_sql_json_length """SELECT json_length('{"k1":"v31","k2":300}')"""
     qt_sql_json_length """SELECT json_length('{"a.b.c":{"k1.a1":"v31", "k2": 300},"a":"niu"}')"""
     qt_sql_json_length """SELECT json_length('{"a":{"k1.a1":"v31", "k2": 300},"b":"niu"}','\$.a')"""
+    qt_sql_json_length """SELECT json_length('abc','\$.k1')"""
 
     qt_select_length """SELECT id, j, json_length(j) FROM ${testTable} ORDER BY id"""
     qt_select_length """SELECT id, j, json_length(j, '\$[1]') FROM ${testTable} ORDER BY id"""