DecodeImage should return null when decoding fails (https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=5759).
DecodeImage should return null when decoding fails (https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=5759).

Danack/ImageMagick,Danack/ImageMagick,Danack/ImageMagick,Danack/ImageMagick,Danack/ImageMagick,Danack/ImageMagick