PDF Display Issue Due to adjustMapping Function

[ren1244]

I have a PDF whose charstrings are encoded in UTF-8, and it uses Unicode characters beyond 0xFFFF. This PDF displays correctly in both Chrome and Adobe Reader DC, but it does not display correctly in Firefox.

Upon reviewing the code, I found an issue in the adjustMapping function at line 488 in the src/core/fonts.js file:

originalCharCode |= 0;

If originalCharCode is greater than 2147483647, this will cause it to become a negative value, resulting in an error. Commenting out this line allows the PDF to display correctly.

Since I am not fully familiar with the details, I am just submitting an issue here.

Attach (recommended) or Link to PDF file here: document.pdf

Configuration:

• Web browser and its version: FireFox 126.0
• Operating system and its version: Windows 11
• PDF.js version: 63b66b4

Steps to reproduce the problem:

1. Clone this repository
2. Open web/viewer.html
3. Open the pdf

What is the expected behavior? (add screenshot)

What went wrong? (add screenshot)