markdown-mode doesn't render maths as expected when killing and undoing.

[PhoenixStarEclipse]

Expected Behavior

Markdown-mode should render maths properly when killing and undoing.

Actual Behavior

Kill and undo-kill upper multiline equations, and lower multiline equations will get unhighlighted.

Steps to Reproduce

1. type

$$a
b$$

$$c
d$$

and make sure that there's an empty line between the two equations.
2. Kill lines $$a and b$$.
3. Undo the two kills by pressing C-/.
4.

$$a
b$$

gets and remains unhighlighted.

Software Versions

• Markdown Mode: 2.4-dev
• Emacs: GNU Emacs 25.3.1 (x86_64-pc-linux-gnu, GTK+ Version 3.22.30) of 2018-07-22
• OS: Linux AprilGrimoire 4.14.52-gentoo #1 SMP Sat Jul 28 20:31:00 CST 2018 x86_64 Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz GenuineIntel GNU/Linux

[PhoenixStarEclipse]

$a$b$c$

is also not properly highlighted. Only a is highlighted, instead of both a and c.

[syohex]

I have merged #487. I suppose #352 (comment) issue is fixed. Please check latest version.

[syohex]

I suppose this issue is emacs problem, not markdown-mode.