Bug of non termination due to floating-point rounding errors

[fmaurica]

Bug of non termination due to floating-point rounding errors found in the following version of ImageMagick:

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$ convert -version
Version: ImageMagick 7.0.4-9 Q16 x86_64 2017-02-14 http://www.imagemagick.org
Copyright: © 1999-2017 ImageMagick Studio LLC
License: http://www.imagemagick.org/script/license.php
Features: Cipher DPC HDRI OpenMP 
Delegates (built-in): png zlib

When launching the following command:

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$ convert flower.png -modulate 100,100,1E25 flower-mod.png

the following function in MagickCore/enhance.c does not terminate:

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static inline void ModulateHSL(const double percent_hue,const double percent_saturation,
                               const double percent_lightness,double *red,double *green,double *blue)

Same problem for the functions ModulateHCL, ModulateHCLp, ModulateHSB, ModulateHSI,
ModulateHSV, ModulateHWB, ModulateLCHab and ModulateLCHuv.
For example non termination of the function ModulateHCL when launching the following command:

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$ convert flower.png -define modulate:colorspace=HCL -modulate 100,100,1E25 flower-mod.png

Other versions of ImageMagick may also be affected.

[magick]

Thanks for the problem report. We can reproduce it and will have a patch to fix it in GIT master branch @ https://github.com/ImageMagick/ImageMagick later today. The patch will be available in the beta releases of ImageMagick @ http://www.imagemagick.org/download/beta/ by sometime tomorrow.

[fmaurica]

You are welcome.