Fix: HBO in CIccCLUT::Interp3d()

[ChrisCoxArt]

Pull Request Checklist

• Have you followed the guidelines in Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same change?
• Have you built your Pull Request locally with the Build Instructions?
• Have you added or updated relevant tests?
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[xsscx]

Maintainer Review

2026-03-01 02:47:43 UTC

Host

Linux 6.6.87.2-microsoft-standard-WSL2 #1 SMP PREEMPT_DYNAMIC Thu Jun  5 18:30:46 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux

Repro

mkdir pr-637
cd pr-637
git clone https://github.com/InternationalColorConsortium/iccDEV.git
cd iccDEV
git fetch origin pull/637/head:pr-637
git checkout pr-637
cd Build
cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_BUILD_TYPE=Debug -Wno-dev -DCMAKE_CXX_FLAGS="-g -fsanitize=address,undefined -fno-sanitize=leak -fno-omit-frame-pointer -Wall" -DENABLE_TOOLS=ON -DENABLE_STATIC_LIBS=ON -DENABLE_SHARED_LIBS=ON Cmake > cmake.log 2>&1
make -j32
wget https://github.com/xsscx/fuzz/raw/refs/heads/master/graphics/icc/npd-CIccMpeCalculator-GetNewApply-IccMpeCalc_cpp-Line4929.icc
printf "'RGB '\nicEncodeFloat\n0.5 0.5 0.5\n" | iccApplyNamedCmm /dev/stdin 3 0 npd-CIccMpeCalculator-GetNewApply-IccMpeCalc_cpp-Line4929.icc 0

Expected Output

'XYZ '  ; Data Format
icEncodeFloat   ; Encoding

;Source Data Format: 'RGB '
;Source Data Encoding: icEncodeFloat
;Source data is after semicolon

;Profiles applied
; npd-CIccMpeCalculator-GetNewApply-IccMpeCalc_cpp-Line4929.icc

    0.0000    0.0000    0.0000  ;    0.5000    0.5000    0.5000