fix several null pointer problems on allocation failure (#526)

cJSON.c

@@ -2548,7 +2548,12 @@ CJSON_PUBLIC(cJSON *) cJSON_CreateIntArray(const int *numbers, int count)
     }
 
     a = cJSON_CreateArray();
-    for(i = 0; a && (i < (size_t)count); i++)
+    if (!a)
+    {
+        return NULL;
+    }
+
+    for(i = 0; i < (size_t)count; i++)
     {
         n = cJSON_CreateNumber(numbers[i]);
         if (!n)
@@ -2584,8 +2589,12 @@ CJSON_PUBLIC(cJSON *) cJSON_CreateFloatArray(const float *numbers, int count)
     }
 
     a = cJSON_CreateArray();
+    if (!a)
+    {
+        return NULL;
+    }
 
-    for(i = 0; a && (i < (size_t)count); i++)
+    for(i = 0; i < (size_t)count; i++)
     {
         n = cJSON_CreateNumber((double)numbers[i]);
         if(!n)
@@ -2621,8 +2630,12 @@ CJSON_PUBLIC(cJSON *) cJSON_CreateDoubleArray(const double *numbers, int count)
     }
 
     a = cJSON_CreateArray();
+    if (!a)
+    {
+        return NULL;
+    }
 
-    for(i = 0;a && (i < (size_t)count); i++)
+    for(i = 0; i < (size_t)count; i++)
     {
         n = cJSON_CreateNumber(numbers[i]);
         if(!n)
@@ -2658,8 +2671,12 @@ CJSON_PUBLIC(cJSON *) cJSON_CreateStringArray(const char *const *strings, int co
     }
 
     a = cJSON_CreateArray();
+    if (!a)
+    {
+        return NULL;
+    }
 
-    for (i = 0; a && (i < (size_t)count); i++)
+    for (i = 0; i < (size_t)count; i++)
     {
         n = cJSON_CreateString(strings[i]);
         if(!n)

tests/cjson_add.c

@@ -117,6 +117,50 @@ static void cjson_add_true_should_fail_on_allocation_failure(void)
     cJSON_Delete(root);
 }
 
+static void cjson_create_int_array_should_fail_on_allocation_failure(void)
+{
+    int numbers[] = {1, 2, 3};
+
+    cJSON_InitHooks(&failing_hooks);
+
+    TEST_ASSERT_NULL(cJSON_CreateIntArray(numbers, 3));
+
+    cJSON_InitHooks(NULL);
+}
+
+static void cjson_create_float_array_should_fail_on_allocation_failure(void)
+{
+    float numbers[] = {1.0f, 2.0f, 3.0f};
+
+    cJSON_InitHooks(&failing_hooks);
+
+    TEST_ASSERT_NULL(cJSON_CreateFloatArray(numbers, 3));
+
+    cJSON_InitHooks(NULL);
+}
+
+static void cjson_create_double_array_should_fail_on_allocation_failure(void)
+{
+    double numbers[] = {1.0, 2.0, 3.0};
+
+    cJSON_InitHooks(&failing_hooks);
+
+    TEST_ASSERT_NULL(cJSON_CreateDoubleArray(numbers, 3));
+
+    cJSON_InitHooks(NULL);
+}
+
+static void cjson_create_string_array_should_fail_on_allocation_failure(void)
+{
+    const char* strings[] = {"1", "2", "3"};
+
+    cJSON_InitHooks(&failing_hooks);
+
+    TEST_ASSERT_NULL(cJSON_CreateStringArray(strings, 3));
+
+    cJSON_InitHooks(NULL);
+}
+
 static void cjson_add_false_should_add_false(void)
 {
     cJSON *root = cJSON_CreateObject();
@@ -390,6 +434,11 @@ int CJSON_CDECL main(void)
     RUN_TEST(cjson_add_true_should_fail_with_null_pointers);
     RUN_TEST(cjson_add_true_should_fail_on_allocation_failure);
 
+    RUN_TEST(cjson_create_int_array_should_fail_on_allocation_failure);
+    RUN_TEST(cjson_create_float_array_should_fail_on_allocation_failure);
+    RUN_TEST(cjson_create_double_array_should_fail_on_allocation_failure);
+    RUN_TEST(cjson_create_string_array_should_fail_on_allocation_failure);
+
     RUN_TEST(cjson_add_false_should_add_false);
     RUN_TEST(cjson_add_false_should_fail_with_null_pointers);
     RUN_TEST(cjson_add_false_should_fail_on_allocation_failure);