bug#489: Mouse highlighting bug

bug#489: Mouse highlighting bug

[Chong Yidong]

There seems to be a bug is how mouse-face highlighting handles extending
faces to the end of the line:

(global-set-key [f1]
  (lambda () (interactive)
    (switch-to-buffer "asdf")
    (erase-buffer)
    (insert "123456\n890")
    (put-text-property 4 9 'mouse-face 'highlight)
    (put-text-property 4 9 'face (list :underline t))))

Put the mouse over the region with mouse-highlight, then remove it.
Result: the space after the first line becomes underlined.

bug#489: marked as done (Mouse highlighting bug)

[Emacs bug Tracking System]

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Your message dated Sun, 21 Jun 2009 22:03:37 -0400
with message-id <87prcxdnye.fsf@stupidchicken.com>
and subject line Re: Mouse highlighting bug
has caused the Emacs bug report #489,
regarding Mouse highlighting bug
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
bug report if necessary, and/or fix the problem forthwith.

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-- 
489: http://emacsbugs.donarmstrong.com/cgi-bin/bugreport.cgi?bug=489
Emacs Bug Tracking System
Contact owner@emacsbugs.donarmstrong.com with problems

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From: Chong Yidong <cyd@stupidchicken.com>
To: emacs-pretest-bug@gnu.org
Subject: Mouse highlighting bug
Date: Thu, 26 Jun 2008 17:39:02 -0400
Message-ID: <87hcbfdgg9.fsf@stupidchicken.com>

There seems to be a bug is how mouse-face highlighting handles extending
faces to the end of the line:

(global-set-key [f1]
  (lambda () (interactive)
    (switch-to-buffer "asdf")
    (erase-buffer)
    (insert "123456\n890")
    (put-text-property 4 9 'mouse-face 'highlight)
    (put-text-property 4 9 'face (list :underline t))))

Put the mouse over the region with mouse-highlight, then remove it.
Result: the space after the first line becomes underlined.



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From: Chong Yidong <cyd@stupidchicken.com>
To: 489-done@emacsbugs.donarmstrong.com
Subject: Re: Mouse highlighting bug
Date: Sun, 21 Jun 2009 22:03:37 -0400
Message-ID: <87prcxdnye.fsf@stupidchicken.com>

> (global-set-key [f1]
>   (lambda () (interactive)
>     (switch-to-buffer "asdf")
>     (erase-buffer)
>     (insert "123456\n890")
>     (put-text-property 4 9 'mouse-face 'highlight)
>     (put-text-property 4 9 'face (list :underline t))))
>
> Put the mouse over the region with mouse-highlight, then remove it.
> Result: the space after the first line becomes underlined.

I've checked a fix for this into the trunk, which involves changing
x_draw_glyph_string so that the underline (and overline) is not extended
into the end-of-line padding.  This is similar to the behavior of
strike-through.