Quarto extension display math edge cases stops extension functionality for rest of document

[johnbest-wdfw]

Bug description

There appears to be a problem with parsing documents after a display math environment that:

1. Includes the $$ characters on the same line as the equation, and
2. has a reference label.

After one of these, the Quarto extension:

1. No longer includes headers in the Outline view in Positron;
2. Does not show the Preview button for that or subsequent display math environments; and
3. Does not recognize any code chunks after the display math environment.

This seems like it might be related to #521 .

Steps to reproduce

Open the following Gist in Positron:

https://gist.github.com/johnbest-wdfw/596c2843b03bfc36cef0eac103b04c16

Observe the behavior in the editor.

Actual behavior

After one or two equations with $$ fences on the same line as the equation and a reference label, section headers and code chunks no longer populate the Outline pane, LaTeX Preview is no longer available, and code chunks cannot be sent to the console, giving an "Editor selection is not within an executable cell" error.

Expected behavior

Section headers and code chunks should always populate the Outline pane, LaTeX Preview should always be available, and code chunks should always be able to be sent to the console.

Your environment

Positron Version: 2026.05.1 (user setup) build 2
Quarto extension version: 1.132.0

Code - OSS Version: 1.109.2
Commit: 80db96acd1bc6f7e7ff5ba4cbc509af8d40af1dd
Date: 2026-05-05T18:02:55.030Z
Electron: 39.3.0
Chromium: 142.0.7444.265
Node.js: 22.21.1
V8: 14.2.231.22-electron.0
OS: Windows_NT x64 10.0.26100