Line overflow in code block causes superposition of text

[specious]

Shrinking the viewport to where at least one line of code inside a code block does not fit fully in the space provided causes such a line to be broken, and rendered on top of the next line. At the same time, the line numbers in the gutter switch to being rendered in the space of one character, such that double and triple digit line numbers are now shown with their digits superimposed.

Here's a code block which fits entirely in the space provided, rendered without problems:

When I add another yada to the comment, the line overflows and is therefore broken, and the superposition happens. At the same time, the gutter rendering is also corrupted for line numbers greater than 9: