Subject: treesit-font-lock-fontify-region unnecessarily re-unfontify's

From: JD Smith <[email-masked]>
Date: Wed, 5 Jun 2024 18:06:54 -0400

The function treesit-font-lock-fontify-region in treesit.el calls (font-lock-unfontify-region start end) right away (see below).  But this function is called as the value of font-lock-fontify-syntactically-function from font-lock-default-fontify-region, which has just itself made the exact same call to font-lock-unfontify-region. I commented out that superfluous call in treesit-font-lock-fontify-region and noticed no ill effects.

(defun treesit-font-lock-fontify-region (start end &optional loudly)
  "Fontify the region between START and END.
If LOUDLY is non-nil, display some debugging information."
  (when (or loudly treesit--font-lock-verbose)
    (message "Fontifying region: %s-%s" start end))
  (treesit-update-ranges start end)
  (font-lock-unfontify-region start end)