Correct lookup table size (caught by go-fuzz)

Author: vcabbage

decode.go

@@ -681,7 +681,7 @@ func readComposite(r reader) (interface{}, error) {
 	return unmarshal(r, iface)
 }
 
-var compositeTypes = [255]func() interface{}{
+var compositeTypes = [256]func() interface{}{
 	typeCodeError:                     func() interface{} { return new(Error) },
 	typeCodeDeleteOnClose:             func() interface{} { return deleteOnClose },
 	typeCodeDeleteOnNoMessages:        func() interface{} { return deleteOnNoMessages },

fuzz_test.go

@@ -332,6 +332,11 @@ func TestFuzzConnCrashers(t *testing.T) {
 			"\xdb\xf1\xbd\xbfwCB@P\x01\x00S(\xc0\x1a\v\xa1\x05/t" +
 			"est@@@@@@@@@@@@@C\x80\x00\x00" +
 			"\x00\x80\x00\x04\x10\x00@@@",
+		24: "\x00\x00\x00d\x02\x00\x00\x00\x00S\x12\xc0\x00\x0e\xa1(p\xbd\xbf\xef" +
+			"\xbd\xdf\uf03d\xbfｿｿｿ\xef\xff\xff\xff\x80" +
+			"\xbd\xbfｿｿ\x00\x02BrXfdw`@CB" +
+			"@P\x01\x00`S(\xc0\x12\v\xa1\x05./est`@@" +
+			"@`\x80@@@@@\x00P\xff\x00\x00\x00@@@`@\x00",
 	}
 
 	for i, tt := range tests {