[Pkg-gmagick-im-team] Bug#814836: imagemagick: Font Metrics faulty textWidth | Integer overflow

[Maximilian Bloch]

Package: imagemagick
Severity: normal

Dear Maintainer,

I seem to have stumbled across an integer overflow issue with imagemagick, pertaining to calculated font metrics (width/bounds) for many fonts depending on pointsize. A more detailed bug report of mine can be found in the ImageMagick Forum:

  https://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=29135 


* What led up to the situation?

$ convert -debug annotate -pointsize 72 -font ./RNS.ttf label:g null:

NOTE RNS.ttf was taken from http://www.1001fonts.com/rns-font.html 


* What was the outcome of this action?

2016-02-15T20:29:34+01:00 0:00.010 0.000u 6.9.3 Annotate convert[3989]: annotate.c/RenderFreetype/1421/Annotate
  Font ./RNS.ttf; font-encoding none; text-encoding none; pointsize 72
2016-02-15T20:29:34+01:00 0:00.010 0.000u 6.9.3 Annotate convert[3989]: annotate.c/GetTypeMetrics/843/Annotate
  Metrics: text: g; width: 3.35545e+07; height: 103; ascent: 70; descent: -31; max advance: 61; bounds: -3.35544e+07,-0.09375  35,55.1719; origin: 36,0; pixels per em: 72,72; underline position: -1.5625; underline thickness: 0.78125


* What outcome did you expect instead?

2016-02-12T06:56:07-05:00 0:00.110 0.010u 7.0.0 Annotate convert[22115]: annotate.c/RenderFreetype/1442/Annotate
  Font ./RNS.ttf; font-encoding none; text-encoding none; pointsize 72
2016-02-12T06:56:07-05:00 0:00.110 0.010u 7.0.0 Annotate convert[22115]: annotate.c/GetTypeMetrics/860/Annotate
  Metrics: text: g; width: 38.5625; height: 103; ascent: 70; descent: -31; max advance: 61; bounds: 0.4375,-0.09375  35,55.1719; origin: 36.2812,0; pixels per em: 72,72; underline position: -1.5625; underline thickness: 0.78125

Any help would be much appreciated.

Thanks,
Max

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