Fix loading null as Guid for object refs in C++ Json parser

Source/Engine/Serialization/JsonTools.cpp

@@ -103,6 +103,28 @@ Matrix JsonTools::GetMatrix(const Value& value)
     return result;
 }
 
+Guid JsonTools::GetGuid(const Value& value)
+{
+    if (value.IsNull())
+        return Guid::Empty;
+    CHECK_RETURN(value.GetStringLength() == 32, Guid::Empty);
+
+    // Split
+    const char* a = value.GetString();
+    const char* b = a + 8;
+    const char* c = b + 8;
+    const char* d = c + 8;
+
+    // Parse
+    Guid result;
+    StringUtils::ParseHex(a, 8, &result.A);
+    StringUtils::ParseHex(b, 8, &result.B);
+    StringUtils::ParseHex(c, 8, &result.C);
+    StringUtils::ParseHex(d, 8, &result.D);
+    return result;
+}
+
+
 DateTime JsonTools::GetDate(const Value& value)
 {
     return DateTime(value.GetInt64());