latex highlight error

[yang-jiaye]

Problem

The latex highlight doesn't display when using "$$...$$" grammar

How to reproduce

I test this error and find that it has 2 trigger condition:

• There has existed a "$$...$$" structure before
• In present "$$...$$" structure, the equation is right next to the first "$$" symbol.

For example

    $$
    \frac{a}{b}=1
    $$
    
    $$
    \frac{a}{b}=2
    $$

    $$
    
    \frac{a}{b}=3
    $$

In this exmaple, the first "$$...$$" structure will show highlight normally, but the second structure will not show highlight, unless you rewrite it as the third structure. The figure is as follows.

Environment

my extension version is 3.4.0 (2020.11.14)
my vscode about is as follows:

版本: 1.61.0 (user setup)
提交: ee8c7def80afc00dd6e593ef12f37756d8f504ea
日期: 2021-10-07T18:13:09.652Z
Electron: 13.5.1
Chrome: 91.0.4472.164
Node.js: 14.16.0
V8: 9.1.269.39-electron.0
OS: Windows_NT x64 10.0.19042

[yzhang-gh]

Thanks. Please see #1008.