fix: json type json-object support empty string key

deps/oblib/src/lib/json_type/ob_json_bin.cpp

@@ -1322,11 +1322,16 @@ int ObJsonBin::deserialize_json_object_v0(const char *data, uint64_t length, ObJ
       } else {
         // TODO if with key dict, read key from dict
         // to consider, add option to controll need alloc or not
-        void *key_buf = allocator_->alloc(key_len);
+        void *key_buf = nullptr;
+        if (key_len > 0) { 
+          key_buf = allocator_->alloc(key_len);
           if (key_buf == NULL) {
             ret = OB_ALLOCATE_MEMORY_FAILED;
             LOG_WARN("fail to alloc memory for data buf", K(ret));
-        } else {
+          }
+        }
+
+        if (OB_SUCC(ret)) {
           MEMCPY(key_buf, data + key_offset, key_len);
           ObString key(key_len, reinterpret_cast<const char*>(key_buf));
           const char *val = data + value_offset;

deps/oblib/src/lib/json_type/ob_json_path.cpp

@@ -1049,7 +1049,7 @@ int ObJsonPath::parse_name_with_rapidjson(char*& str, uint64_t& len)
     ObJsonString *val = static_cast<ObJsonString *>(dom);
     len = val->value().length();
     str = static_cast<char*> (allocator_->alloc(len));
-    if (OB_ISNULL(str)) {
+    if (len > 0 && OB_ISNULL(str)) {
       ret = OB_ALLOCATE_MEMORY_FAILED;
       LOG_WARN("fail to allocate memory for member_name.",
         K(ret), K(len), K(val->value()));

deps/oblib/src/lib/json_type/ob_json_tree.cpp

@@ -628,9 +628,6 @@ int ObJsonObject::add(const common::ObString &key, ObJsonNode *value)
   if (OB_ISNULL(value)) { // check param
     ret = OB_INVALID_ARGUMENT;
     LOG_WARN("param value is NULL", K(ret));
-  } else if (key.empty()) {
-    ret = OB_ERR_JSON_DOCUMENT_NULL_KEY;
-    LOG_WARN("key is NULL", K(ret));
   } else {
     value->set_parent(this);
     ObJsonObjectPair pair(key, value);

src/sql/engine/expr/ob_expr_json_search.cpp

@@ -262,7 +262,7 @@ int ObExprJsonSearch::eval_json_search(const ObExpr &expr, ObEvalCtx &ctx, ObDat
   }
 
   // check one_or_all flag
-  bool one_flag;
+  bool one_flag = false;
   if (OB_SUCC(ret) && !is_null) {
     json_arg = expr.args_[1];
     val_type = json_arg->datum_meta_.type_;

src/sql/engine/expr/ob_expr_json_value.cpp

@@ -1151,7 +1151,7 @@ int ObExprJsonValue::cast_to_res(common::ObIAllocator *allocator,
     case ObMediumIntType:
     case ObInt32Type:
     case ObIntType: {
-      int64_t val;
+      int64_t val = 0;
       ret = cast_to_int(j_base, dst_type, val);
       if (!try_set_error_val<ObDatum>(res, ret, error_type, error_val, "SIGNED")) {
         res.set_int(val);
@@ -1163,7 +1163,7 @@ int ObExprJsonValue::cast_to_res(common::ObIAllocator *allocator,
     case ObUMediumIntType:
     case ObUInt32Type:
     case ObUInt64Type: {
-      uint64_t val;
+      uint64_t val = 0;
       ret = cast_to_uint(j_base, dst_type, val);
       if (!try_set_error_val<ObDatum>(res, ret, error_type, error_val, "UNSIGNED")) {
         res.set_uint(val);
@@ -1171,7 +1171,7 @@ int ObExprJsonValue::cast_to_res(common::ObIAllocator *allocator,
       break;
     }
     case ObDateTimeType: {
-      int64_t val;
+      int64_t val = 0;
       ret = cast_to_datetime(j_base, accuracy, val);
       if (ret == OB_ERR_NULL_VALUE) {
         res.set_null();
@@ -1192,7 +1192,7 @@ int ObExprJsonValue::cast_to_res(common::ObIAllocator *allocator,
       break;
     }
     case ObDateType: {
-      int32_t val;
+      int32_t val = 0;
       ret = cast_to_date(j_base, val);
       if (!try_set_error_val<ObDatum>(res, ret, error_type, error_val, "DATE")) {
         res.set_date(val);
@@ -1200,7 +1200,7 @@ int ObExprJsonValue::cast_to_res(common::ObIAllocator *allocator,
       break;
     }
     case ObTimeType: {
-      int64_t val;
+      int64_t val = 0;
       ret = cast_to_time(j_base, accuracy, val);
       if (!try_set_error_val<ObDatum>(res, ret, error_type, error_val, "TIME")) {
         res.set_time(val);
@@ -1208,7 +1208,7 @@ int ObExprJsonValue::cast_to_res(common::ObIAllocator *allocator,
       break;
     }
     case ObYearType: {
-      uint8_t val;
+      uint8_t val = 0;
       ret = cast_to_year(j_base, val);
       if (!try_set_error_val<ObDatum>(res, ret, error_type, error_val, "YEAR")) {
         res.set_year(val);
@@ -1217,7 +1217,7 @@ int ObExprJsonValue::cast_to_res(common::ObIAllocator *allocator,
     }
     case ObFloatType:
     case ObUFloatType: {
-      float out_val;
+      float out_val = 0;
       ret = cast_to_float(j_base, dst_type, out_val);
       if (!try_set_error_val<ObDatum>(res, ret, error_type, error_val, "FLOAT")) {
         res.set_float(out_val);
@@ -1226,7 +1226,7 @@ int ObExprJsonValue::cast_to_res(common::ObIAllocator *allocator,
     }
     case ObDoubleType:
     case ObUDoubleType: {
-      double out_val;
+      double out_val = 0;
       ret = cast_to_double(j_base, dst_type, out_val);
       if (!try_set_error_val<ObDatum>(res, ret, error_type, error_val, "DOUBLE")) {
         res.set_double(out_val);
@@ -1268,7 +1268,7 @@ int ObExprJsonValue::cast_to_res(common::ObIAllocator *allocator,
       break;
     }
     case ObBitType: {
-      uint64_t out_val;
+      uint64_t out_val = 0;
       ret = cast_to_bit(j_base, out_val);
       if (!try_set_error_val<ObDatum>(res, ret, error_type, error_val, "BIT")) {
         res.set_bit(out_val);