Inaccurate saving of NSMB2 PTCL binary

[ExplosBlue]

Description

Opening NSMB2's PTCL binary in the editor and saving it without making any modifications produces a file that differs from the original by 3 bytes.

Steps to Reproduce

1. Open NSMB2's PTCL binary in the editor.
2. Save the file without changing any data.
3. Compare the original and saved binaries using a binary diff tool.

Expected Behavior

Saving a PTCL file without user modifications should produce a binary that is identical to the original input file.

Notes

The mismatch occurs within the texture format metadata of a child emitter.

In Nintendo’s original binary:

• The emitter references the texture as 16×16 L8, with a size of 256 bytes.

However:

• All other references to the same texture describe it as 16×64 LA88, with a size of 2048 bytes.
• The editor re-serializes the texture using this latter format (16×64 LA88, 2048 bytes), which appears internally consistent and matches other references.

This raises the possibility that the original PTCL file contains inconsistent or erroneous texture metadata produced by Nintendo’s tooling.