Fix a Bug Without Breaking Things

Fill these in and the prompt below updates as you type. Anything you leave blank stays as a placeholder.

I have a bug: {{bug_description}}

Expected behavior: {{expected}}
Actual behavior: {{actual}}

Here's the relevant code:
{{code}}

Before suggesting a fix:
- Identify all code paths affected.
- Check if the fix could break any existing functionality.
- Look for other places in the code with the same pattern (they might have the same bug).

Then provide: the minimal fix (smallest change that solves the problem), an explanation of why it works, a test case that proves the bug is fixed, and a test case that proves existing functionality still works.