fix drawing highlight when in insert mode at the end of a line

src/gui/BufferPane.cc

@@ -314,7 +314,12 @@ int BufferPane::draw_buffer_line(int screen_row, const Buffer::Iterator & start_
             {
                 int row = draw_row;
                 int col = screen_column;
-                for (int i = 0; i < character_width; i++)
+                int c_w = character_width;
+                if (insert_mode() && (code_point == '\n'))
+                {
+                    c_w = 1;
+                }
+                for (int i = 0; i < c_w; i++)
                 {
                     draw_crosshair(col_x(col), row_y(row));
                     col++;