Subject: bug#16647: Imprecisions with window-resizing cursors

From: [email-masked] (N. Jackson)
Date: Fri, 14 Feb 2014 18:53:07 -0400

martin rudalics <[email-masked]> writes:

> Can you please try conducting the same experiments with emacs -Q
>
> (set-frame-parameter nil 'right-divider-width 6)
>
> and with scrollbars en-/and disabled?

emacs -Q
M-: (set-frame-parameter nil 'right-divider-width 6)
M-x split-window-right

With this I see Evgeni's original bug -- when the <=> handle first
appears beyond the vertical line, clicking on it and dragging has no
effect, if just disappears and returns to a normal cursor. It's
disorienting behaviour but I think it might be due to the lag --
i.e. maybe it's about to turn back to the normal mouse cursor but hasn't
gotten around to actually doing so yet.

I do _not_ see my "Another bug" with this configuration -- when the
vertical line is at its extreme left or right position, it doesn't
matter from which side one approaches it, one still get's the <=> handle
displayed.

emacs -Q
M-: (progn
  (scroll-bar-mode -1) (set-frame-parameter nil 'right-divider-width 6)
  (split-window-right) )

With this recipe I see nothing wrong at all (except for the
sluggishness).

Also I have a slight amendment to what I wrote earlier about my "Another
bug":

>> Another bug =========== When the vertical line is as far to the right
>> in the frame as it will go (i.e., when the right window is as narrow
>> as permitted), then the <=> handle only appears when the mouse cursor
>> approaches the vertical line from the right. If the mouse cursor
>> approaches the vertical line from the left, the <=> handle fails to
>> appear. (Ditto with "left" and "right" reversed in that statement.)
>
> Interesting.  I cannot observe that here.

I double checked this. I definitely see this happening, but I was
mistaken about the "ditto". When the vertical line is as far to the left
as it will go, the <=> handle only appears when the mouse cursor
approaches the vertical line from the _right_ -- the same direction as
for the case with the vertical line as far to the left as it will go.