+ && ydiff < double_click_fuzz && ydiff > - double_click_fuzz
+ /* Maybe the mouse has moved a lot, caused scrolling, and
+ eventually ended up at the same screen position (but
+ not buffer position) in which case it is a drag, not
+ a click. */
+ /* FIXME: OTOH if the buffer position has changed
+ because of a timer or process filter rather than
+ because of mouse movement, it should be considered as
+ a click. But mouse-drag-region completely ignores
+ this case and it hasn't caused any real problem, so
+ it's probably OK to ignore it as well. */
+ && EQ (Fcar (Fcdr (start_pos)), Fcar (Fcdr (position))))