OSV-2020-1185 Global-buffer-overflow in kencodingprober::nsCodingStateMachine::NextState

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=12919 Crash type: Global-buffer-overflow READ 4 Crash state: kencodingprober::nsCodingStateMachine::NextState kencodingprober::nsEscCharSetProber::HandleData kencodingprober::nsUniversalDetector::HandleData...