graphicsmagick/coder_XPM_fuzzer: Use-of-uninitialized-value in IsMonochromeImage

Project: http://hg.code.sf.net/p/graphicsmagick/code Detailed report: https://oss-fuzz.com/testcase?key=4799209178923008 Project: graphicsmagick Fuzzer: libFuzzergraphicsmagickcoderXPMfuzzer Fuzz target binary: coderXPMfuzzer Job Type: libfuzzermsangraphicsmagick Platform Id: linux Crash Type:...