if end pointer non null, assumes end of string

cJSON.c

@@ -1013,7 +1013,11 @@ CJSON_PUBLIC(cJSON *) cJSON_ParseWithOpts(const char *value, const char **return
     }
 
     buffer.content = (const unsigned char*)value;
-    buffer.length = strlen((const char*)value) + sizeof("");
+    if(return_parse_end && *return_parse_end){
+        buffer.length = (size_t)(*return_parse_end - value);
+    }else{
+        buffer.length = strlen((const char*)value) + sizeof("");
+    }
     buffer.offset = 0;
     buffer.hooks = global_hooks;
 

tests/CMakeLists.txt

@@ -42,6 +42,7 @@ if(ENABLE_CJSON_TEST)
     set(unity_tests
         parse_examples
         parse_number
+        parse_memory
         parse_hex4
         parse_string
         parse_array

tests/parse_memory.c

@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "common.h"
+#include "unity/examples/unity_config.h"
+#include "unity/src/unity.h"
+
+static void parse_memory_should_parse_true(void) {
+    cJSON *item;
+    const char *mem =
+                   "{"
+                   "\"hello\":\"world\""
+                   "}",
+               *end = mem + strlen(mem);
+    item = cJSON_ParseWithOpts(mem, &end, false);
+    TEST_ASSERT_NOT_NULL(item);
+    cJSON_Delete(item);
+}
+
+int main(void) {
+    /* initialize cJSON item */
+    UNITY_BEGIN();
+    RUN_TEST(parse_memory_should_parse_true);
+    return UNITY_END();
+}