Re: [hober0@gmail.com: Re: mode-line redisplay bug]

[Jason Rumney <jasonr@gnu.org>]

YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp> writes:

> A simple debug code below shows the incorrectness of the calculated
> rectangle :-).

The debugging code you posted was for glyph_rect, which was not
affected by my patch. But this does show that there are problems with
all this code to detect mouse motion and throttle the movement events.

You debugging code appears to highlight the glyph below the one the
mouse is currently over.

This if statement seems to be wrong:

      if (r->y >= y)

Where y is the mouse position and r->y is the top of the glyph.

If r->y > y, then we have already reached the glyph below the one we
want. The only case where this works correctly is when the mouse
pointer is over the top edge of the glyph so r->y == y.

I think this needs to be:

      if (r->y + r->height > y)

I will do some more testing, and check in the changes when I think I
have got it right.