Dash breaks code block display

[silopolis]

A dash as the first non-blank character somehow breaks display/indentation of that line in "edit mode".

Here is a screenshot of trying to edit some YAML code.

Each line "starting" with a - (a dash and a space) is shifted left (collision with list stuff?) as soon as the space is added.
Moreover, the display is shifted one step further to the left for each space added at the beginning of the line or between the dash and the rest of the line content.

Edit: Also, highlight.js seems broken too as you can see in the last capture.