The formula insert block gets too wide when a formula is long

[cuchulainn-fun]

Bug Report

Expected behavior
When a user insert a long formula in the latex block, that the block doesn't expands beyond the writting area.
For the user experience, it would be interesting for the block to resize in order to always remain in the the writting area.

Actual behavior
When a user insert a long formula in the latex block, the block expands beyond the writting area.

However, the formula itself is displayed in the write area as soon as you exit the block (behavior after formula insertion) :

Steps to Reproduce

1. Add an Latex formula block in the post
2. Then paste a long formula in the block, for example this one : \frac{1}{\Bigl(\sqrt{\phi \sqrt{5}}-\phi\Bigr) e^{\frac25 \pi}} \equiv 1+\frac{e^{-2\pi}} {1+\frac{e^{-4\pi}} {1+\frac{e^{-6\pi}} {1+\frac{e^{-8\pi}} {1+\cdots} } } }
3. And then you'll see that the block expands beyond the writting area

Environment

• Platform: edx platform when Ashley is in

Additional context/Screenshots

Illustration of the behavior in action :