add loop check for json_object_update_recursive function

src/value.c

@@ -37,7 +37,7 @@ static JSON_INLINE int isnan(double x) { return x != x; }
 static JSON_INLINE int isinf(double x) { return !isnan(x) && isnan(x - x); }
 #endif
 
-json_t *do_deep_copy(const json_t *, hashtable_t *);
+json_t *do_deep_copy(const json_t *json, hashtable_t *parents);
 
 static JSON_INLINE void json_init(json_t *json, json_type type)
 {
@@ -214,24 +214,56 @@ int json_object_update_missing(json_t *object, json_t *other)
     return 0;
 }
 
-int json_object_update_recursive(json_t *object, json_t *other)
+int do_object_update_recursive(json_t *object, json_t *other, hashtable_t *parents)
 {
     const char *key;
     json_t *value;
+    char loop_key[LOOP_KEY_LEN];
+    int res = 0;
 
     if(!json_is_object(object) || !json_is_object(other))
         return -1;
 
+    if(jsonp_loop_check(parents, other, loop_key, sizeof(loop_key)))
+        return -1;
+
     json_object_foreach(other, key, value) {
         json_t *v = json_object_get(object, key);
 
         if(json_is_object(v) && json_is_object(value))
-            json_object_update_recursive(v, value);
+        {
+            if(do_object_update_recursive(v, value, parents))
+            {
+                res = -1;
+                break;
+            }
+        }
         else
-            json_object_set_nocheck(object, key, value);
+        {
+            if(json_object_set_nocheck(object, key, value))
+            {
+                res = -1;
+                break;
+            }
+        }
     }
 
-    return 0;
+    hashtable_del(parents, loop_key);
+
+    return res;
+}
+
+int json_object_update_recursive(json_t *object, json_t *other)
+{
+    int res;
+    hashtable_t parents_set;
+
+    if (hashtable_init(&parents_set))
+        return -1;
+    res = do_object_update_recursive(object, other, &parents_set);
+    hashtable_close(&parents_set);
+
+    return res;
 }
 
 void *json_object_iter(json_t *json)
@@ -349,7 +381,7 @@ static json_t *json_object_deep_copy(const json_t *object, hashtable_t *parents)
 
     result = json_object();
     if(!result)
-        return NULL;
+        goto out;
 
     /* Cannot use json_object_foreach because object has to be cast
        non-const */
@@ -368,6 +400,8 @@ static json_t *json_object_deep_copy(const json_t *object, hashtable_t *parents)
         }
         iter = json_object_iter_next((json_t *)object, iter);
     }
+
+out:
     hashtable_del(parents, loop_key);
 
     return result;
@@ -668,7 +702,7 @@ static json_t *json_array_deep_copy(const json_t *array, hashtable_t *parents)
 
     result = json_array();
     if(!result)
-        return NULL;
+        goto out;
 
     for(i = 0; i < json_array_size(array); i++)
     {
@@ -679,6 +713,8 @@ static json_t *json_array_deep_copy(const json_t *array, hashtable_t *parents)
             break;
         }
     }
+
+out:
     hashtable_del(parents, loop_key);
 
     return result;

test/suites/api/test_object.c

@@ -209,7 +209,7 @@ static void test_conditional_updates()
 
 static void test_recursive_updates()
 {
-    json_t *invalid, *object, *other;
+    json_t *invalid, *object, *other, *barBefore, *barAfter;
 
     invalid = json_integer(42);
 
@@ -241,6 +241,10 @@ static void test_recursive_updates()
 
     object = json_pack("{sis{si}}", "foo", 1, "bar", "baz", 2);
     other = json_pack("{s{si}}", "bar", "baz", 3);
+    barBefore = json_object_get(object, "bar");
+
+    if(!barBefore)
+        fail("can't get bar object before json_object_update_recursive");
 
     if(json_object_update_recursive(object, other))
         fail("json_object_update_recursive failed");
@@ -254,6 +258,33 @@ static void test_recursive_updates()
     if(json_integer_value(json_object_get(json_object_get(object, "bar"), "baz")) != 3)
         fail("json_object_update_recursive failed to update nested value");
 
+    barAfter = json_object_get(object, "bar");
+    if(!barAfter)
+        fail("can't get bar object after json_object_update_recursive");
+
+    if(barBefore != barAfter)
+        fail("bar object reference changed after json_object_update_recursive");
+
+    json_decref(object);
+    json_decref(other);
+
+    /* check circular reference */
+    object = json_pack("{s{s{si}}}", "foo", "bar", "baz", 2);
+    other = json_pack("{s{s{si}}}", "foo", "bar", "baz", 2);
+    json_object_set(json_object_get(json_object_get(object, "foo"), "bar"), "baz",
+                    json_object_get(other, "foo"));
+    json_object_set(json_object_get(json_object_get(other, "foo"), "bar"), "baz",
+                    json_object_get(other, "foo"));
+
+    if(!json_object_update_recursive(object, other))
+        fail("json_object_update_recursive update a circular reference!");
+
+    json_object_set_new(json_object_get(json_object_get(other, "foo"), "bar"), "baz",
+                        json_integer(1));
+
+    if(json_object_update_recursive(object, other))
+        fail("json_object_update_recursive failed!");
+
     json_decref(object);
     json_decref(other);
 }