graphicsmagick/coder_MNG_fuzzer: Use-of-uninitialized-value in ReadMNGImage

Project: http://hg.code.sf.net/p/graphicsmagick/code Detailed report: https://oss-fuzz.com/testcase?key=5659249254858752 Project: graphicsmagick Fuzzer: libFuzzergraphicsmagickcoderMNGfuzzer Fuzz target binary: coderMNGfuzzer Job Type: libfuzzermsangraphicsmagick Platform Id: linux Crash Type:...