[cairo-bugs] [Bug 48222] Glyph corruption in evince with cairo 1.12

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=48222

Adrian Johnson <ajohnson at redneon.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|poppler-bugs at lists.freedesk |cworth at cworth.org
                   |top.org                     |
          QAContact|                            |cairo-bugs at cairographics.or
                   |                            |g
                 CC|                            |chris at chris-wilson.co.uk
            Product|poppler                     |cairo
            Version|unspecified                 |1.12.0
          Component|cairo backend               |general

--- Comment #2 from Adrian Johnson <ajohnson at redneon.com> 2012-04-08 02:27:54 UTC ---
The font metrics returned by poppler look correct to me. They are all similar
to:

x_scale: 0.120000 y_scale: -0.120000  x_bearing: 4.000000  y_bearing: 0.000000 
width: 79.000000  height: 85.000000  x_advance: 88.000000  y_advance: 0.000000

x_scale: 0.120000 y_scale: -0.120000  x_bearing: 6.000000  y_bearing: -2.000000
 width: 52.000000  height: 86.000000  x_advance: 65.000000  y_advance: 0.000000

x_scale: 0.120000 y_scale: -0.120000  x_bearing: 5.000000  y_bearing: 0.000000 
width: 68.000000  height: 82.000000  x_advance: 80.000000  y_advance: 0.000000

x_scale: 0.120000 y_scale: -0.120000  x_bearing: 4.000000  y_bearing: 0.000000 
width: 76.000000  height: 81.000000  x_advance: 85.000000  y_advance: 0.000000

The problem also occurs with the PS output. I compared the PS output between
1.10.2 and 1.12.0. The fonts are all the same - same metrics, same image data.
The difference is that in the page content there is a 1 point high clip before
each show glyphs. eg

97 666 1 -1 re W n        <---- here
0 g
BT
0.12 0 0 -0.12 97.08 665.22 Tm
/f-0-0 1 Tf
<00>Tj
ET
Q q
113 666 8 -1 re W n         <---- here
0 g
BT
0.12 0 0 -0.12 112.32 665.22 Tm
/f-0-0 1 Tf
<0102>Tj
ET
Q q
138 666 26 -1 re W n    <---- here
0 g
BT
0.12 0 0 -0.12 137.88 665.22 Tm
/f-0-0 1 Tf
<03040005>Tj
ET


This is not present in the 1.10.2 PS output. When I remove these lines the file
renders correctly.

git bisect tells me the offending cairo commit is:

commit b132fae5e843c329d1414d1a65b2e8d66b99852f
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Thu Jul 14 21:19:54 2011 +0100

    clip: Rudimentary support for clip-polygon extraction

Poppler is not generating the clips before each showing glyph. So even if the
clip boxes were the correct size they still should not appear in the PS output.

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA Contact for the bug.