Problem

After updating Magit package in Doom Emacs, syntax highlighting and fonts stopped rendering correctly in PR diffs.

works with: https://github.com/magit/magit/commits/v4.3.8/
breaks at: https://github.com/magit/magit/commits/v4.4.0/

Root Cause

From the Magit v4.4.0 changelog:

"All text inserted into Magit buffers that previously used face now use font-lock-face and magit-section-mode can therefore set font-lock-defaults. Previously if some third-party packages used font-lock-add-keywords, some of Magit's own fontification would be lost. Third-party packages that use magit-section-mode, might need to be adjusted accordingly."

The Breaking Change:

• Magit switched from using the face text property to font-lock-face
• pr-review was only looking for overlays with the face property
• pr-review buffers weren't activating font-lock-mode to render font-lock-face

The pr-review package transfers overlays to text properties (since overlays don't survive buffer copying), but the old detection logic only looked for overlays with the specific 'diff-mode property.