I discovered this by accident.
Yes, this bug is harmless, but bug is bug.
> when you mark a single line
No. I used this from the beginning on, and this even works, if the cursor stands somewhere in the middle of a line with no text selected. If you then press Ctrl+B, the whole line gets commented.
So does the IDE, if the cursor stands at the end of a line (last column).
As it works without selected text, it would be nice if this behaviour would be more consistent.
> it's quicker to just press the [;]
Errrr... No. Of course, it depends on the certain situation, but I have the situation that I click here and there with the mouse in the right hand and comment/uncomment single lines of code with Ctrl/Alt+B to debug my code. So leaving the mouse to use both hands to press this combo would consume incredibly 1 second more time!