Floating Point Domain Error triggered by IdentifyBuiltinColorSpace()

[stolk]

IdentifyBuiltinColorSpace() applies transformations on pixel values that can leave the pixel value containing negative values.

Subsequently, when a gamma curve is applied in OpenColorIO_v2_4dev::GammaMoncurveOpCPURev::apply() the powf() function is called with a negative base and a fractional power, which causes a domain error.

This leads to a SIGFPE and will abort applications that have floating point exceptions enabled.

#0  0x00007ffff6fb9c4e in __math_invalidf (x=-0.0485877097) at ../sysdeps/ieee754/flt-32/math_errf.c:80
#1  0x00007ffff50f6271 in std::pow (__x=-0.0485877097, __y=0.416666657) at /usr/bin/../lib/gcc/x86_64-linux-gnu/13/../../../../include/c++/13/cmath:373
#2  0x00007ffff535681f in OpenColorIO_v2_4dev::GammaMoncurveOpCPURev::apply (this=0x555556e01fa0, inImg=0x555556e2e190, outImg=0x555556e2e190, numPixels=5)
    at /home/stolk/src/OpenColorIO/src/OpenColorIO/ops/gamma/GammaOpCPU.cpp:634
#3  0x00007ffff5583874 in OpenColorIO_v2_4dev::GenericScanlineHelper<float, float>::finishRGBAScanline (this=0x555556ebe780)
    at /home/stolk/src/OpenColorIO/src/OpenColorIO/ScanlineHelper.cpp:164
#4  0x00007ffff517e898 in OpenColorIO_v2_4dev::CPUProcessor::Impl::apply (this=0x555556e0be20, srcImgDesc=..., dstImgDesc=...)
    at /home/stolk/src/OpenColorIO/src/OpenColorIO/CPUProcessor.cpp:431
#5  0x00007ffff517edbd in OpenColorIO_v2_4dev::CPUProcessor::apply (this=0x555556e7b3b0, srcImgDesc=..., dstImgDesc=...)
    at /home/stolk/src/OpenColorIO/src/OpenColorIO/CPUProcessor.cpp:543
#6  0x00007ffff516dec3 in OpenColorIO_v2_4dev::ConfigUtils::isIdentityTransform (
    proc=std::shared_ptr<const OpenColorIO_v2_4dev::Processor> (use count 1, weak count 0) = {...}, RGBAvals=std::vector of length 20, capacity 20 = {...}, 
    absTolerance=0.00100000005) at /home/stolk/src/OpenColorIO/src/OpenColorIO/ConfigUtils.cpp:262
#7  0x00007ffff51704db in OpenColorIO_v2_4dev::ConfigUtils::IdentifyBuiltinColorSpace (
    srcConfig=std::shared_ptr<const OpenColorIO_v2_4dev::Config> (use count 2, weak count 0) = {...}, 
    builtinConfig=std::shared_ptr<const OpenColorIO_v2_4dev::Config> (use count 2, weak count 0) = {...}, builtinColorSpaceName=0x7ffff7bef833 "srgb_tx")
    at /home/stolk/src/OpenColorIO/src/OpenColorIO/ConfigUtils.cpp:826
#8  0x00007ffff513f025 in OpenColorIO_v2_4dev::Config::IdentifyBuiltinColorSpace (
    srcConfig=std::shared_ptr<const OpenColorIO_v2_4dev::Config> (use count 2, weak count 0) = {...}, 
    builtinConfig=std::shared_ptr<const OpenColorIO_v2_4dev::Config> (use count 2, weak count 0) = {...}, builtinColorSpaceName=0x7ffff7bef833 "srgb_tx")
    at /home/stolk/src/OpenColorIO/src/OpenColorIO/Config.cpp:2911
#9  0x00007ffff79b3a38 in OpenImageIO_v2_6_7::ColorConfig::Impl::IdentifyBuiltinColorSpace (this=0x555556e00de0, name=0x7ffff7bef833 "srgb_tx")
    at /home/stolk/src/OpenImageIO/src/libOpenImageIO/color_ocio.cpp:770
#10 0x00007ffff79b2746 in OpenImageIO_v2_6_7::ColorConfig::Impl::identify_builtin_equivalents (this=0x555556e00de0)
    at /home/stolk/src/OpenImageIO/src/libOpenImageIO/color_ocio.cpp:729
#11 0x00007ffff79b4743 in OpenImageIO_v2_6_7::ColorConfig::Impl::init (this=0x555556e00de0, filename=...)
    at /home/stolk/src/OpenImageIO/src/libOpenImageIO/color_ocio.cpp:835
#12 0x00007ffff79b3d1e in OpenImageIO_v2_6_7::ColorConfig::reset (this=0x7ffff7f975e0 <OpenImageIO_v2_6_7::ColorConfig::default_colorconfig()::config>, filename=...)
    at /home/stolk/src/OpenImageIO/src/libOpenImageIO/color_ocio.cpp:882
#13 0x00007ffff79b3ac7 in OpenImageIO_v2_6_7::ColorConfig::ColorConfig (this=0x7ffff7f975e0 <OpenImageIO_v2_6_7::ColorConfig::default_colorconfig()::config>, 
    filename=...) at /home/stolk/src/OpenImageIO/src/libOpenImageIO/color_ocio.cpp:780
#14 0x00007ffff79aff2e in OpenImageIO_v2_6_7::ColorConfig::default_colorconfig () at /home/stolk/src/OpenImageIO/src/libOpenImageIO/color_ocio.cpp:67
#15 0x00007ffff7b223a9 in OpenImageIO_v2_6_7::PNG_pvt::write_info[abi:cxx11](png_struct_def*&, png_info_def*&, int&, OpenImageIO_v2_6_7::ImageSpec&, std::vector<png_text_struct, std::allocator<png_text_struct> >&, bool&, bool&, float&) (sp=@0x555556e04268: 0x555556e8b260, ip=@0x555556e04270: 0x555556ddda10, 
    color_type=@0x555556e0427c: 6, spec=..., text=std::vector of length 0, capacity 0, convert_alpha=@0x555556e04280: true, srgb=@0x555556e04282: false, 
    gamma=@0x555556e04284: 1) at /home/stolk/src/OpenImageIO/src/png.imageio/png_pvt.h:607
#16 0x00007ffff7b7746e in OpenImageIO_v2_6_7::PNGOutput::open (this=0x555556e04190, name="imageinout_test-png.png", userspec=..., 
    mode=OpenImageIO_v2_6_7::ImageOutput::Create) at /home/stolk/src/OpenImageIO/src/png.imageio/pngoutput.cpp:218
#17 0x0000555555564d59 in checked_write (out=0x555556e04190, filename=..., spec=..., type=..., data=0x555556de6e20, do_asserts=true, errmsg=0x0, ioproxy=0x0)
    at /home/stolk/src/OpenImageIO/src/libOpenImageIO/imageinout_test.cpp:124
#18 0x0000555555563728 in test_all_formats () at /home/stolk/src/OpenImageIO/src/libOpenImageIO/imageinout_test.cpp:393
#19 0x0000555555562db6 in main (argc=2, argv=0x7fffffffdcd8) at /home/stolk/src/OpenImageIO/src/libOpenImageIO/imageinout_test.cpp:550

From the powf() manual page:

If x is a finite value less than 0, and y is a finite noninteger, a domain error occurs, and a NaN is returned.

OpenColorIO should not be calling powf() on negative values.