If you drag from some point in the middle of a line towards the right, you can select the rest of the text to the end of the line (and can verify that by copying it to the clipboard), but the rectangular selection area often doesn't cover the last character even though it's selected. Whereas if you drag downwards to select part of the next line too, the first line's selection is correct. Probably has something to do with attempting to leave out the terminator (null or CRLF?)