If you have some blank lines in elm_code, in edi, ecrire, etc. Then lose focus on that window for another or the desktop. The gray text entry area does not fill the entire width. There is a gap at the far right, which shows black like the background.
As seen in this screenshot on the right of the EDI window.
Also when you type in text, it seems to fill in that area. However the text cannot enter that same area. In this screenshot, I cannot type another 1 such that the cursor is right on the edge. If I scroll back. the text is on the edge because there is more, but not otherwise. Seems like that is related to the one above. Just the other happens when no text. Most editors will place text/cursor right up to the very edge. Maybe a spacing issue not sure.
Example of another going to edge. The cursor is touching the right edge. Next char moves others over. But no gap like in the 2nd screenshot of EDI.