Subject: 23.2; Raise display property does not work correctly on Mac OS X

From: David Aspinall <[email-masked]>
Date: Tue, 21 Jun 2011 16:45:33 +0100

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The raise display property does not work properly on Mac OS X.  This
spoils the display of subscripts and superscripts in TeX modes, for
example, and ruins the display of mathematics used in Proof General 
(http://proofgeneral.inf.ed.ac.uk).

Simple recipe to demonstrate: evaluate the lines below in the *scratch* buffer:

(progn
  (goto-char (point-min))
  (put-text-property (+ 5 (point)) (+ 10 (point)) 'display '(raise  0.5)))

On Mac OS, this (as far as I can tell) results in the whole line being
shifted, not just the 5 characters with the property.  In Linux, you see
the desirable effect that the five characters are raised from the
baseline of the rest of the line.

This bug has been present for some time, although (IIRC) the previous
native port which became the official GNU port produced the right
effect.

- David Aspinall

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Content-Type: image/png
Content-Disposition: attachment; filename=display-raise-linux.png
Content-Transfer-Encoding: base64
Content-Description: display raise example on Linux (Emacs 23.2.1)

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Content-Type: image/png
Content-Disposition: attachment; filename=display-raise-mac.png
Content-Transfer-Encoding: base64
Content-Description: display raise example on Mac (Emacs 23.2.1)

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