Highlight of first heredoc with quotes broken depending on how many characters exists before it

[flaviovs]

It took me some time to replicate this with a minimal example: when the file below loads, the single quote inside the heredoc is interpreted as an opening string, breaking the highlight from there downwards. Now the strangest things:

• If I remove one single character before the heredoc, the file loads with highlighting working fine.
• If I do any edit anywhere before the heredoc -- either adding or removing characters -- then highlighting is fixed.

Can anyone replicate this? Perhaps a font-lock issue?

<?php

//....................

class Test
{
 public function a12345678()
{
 //........
 //................................................
 //........................
 //.....................................
 //....................................................
 //....
 //
 }

 public function a123456789012345678901()
{
 // .................

 // ..............
 // ........
 // .

 echo <<<EOTXT
 I'm here.
 EOTXT;
 }

 public function notHighlighted()
{
 }
}

Here's how it looks in my computer:

Stock Debian Emacs 28.2, php-mode-20240621.742 from ELPA.

[zonuexe]

@flaviovs Thank you for your report!

The number 500 is based on the default value of syntax-propertize-chunk-size, which was introduced in #531 to improve performance. Your report was an important clue to the problem with the previous approach.

We are very grateful for your bug report.

[flaviovs]

Glad I could help. Thanks for looking into this, @zonuexe.