[Bug]:source判空问题

### Describe the bug

<img width="971" height="361" alt="Image" src="https://github.com/user-attachments/assets/704946bd-d106-44bf-95bb-7755d848ebef" />

### To Reproduce

?

### Expected behavior

?

### Screenshots

_No response_

### Platform

Windows 10

### BDS Version

1.21.93

### LeviLamina Version

1.4.4

### LegacyScriptEngine Version

0.13.2

### Additional context

_No response_