caught error where the length of data is zero in the header

Signed-off-by: GuptaManan100 <manan@planetscale.com>

go/mysql/conn.go

@@ -860,6 +860,9 @@ func (c *Conn) handleNextCommand(handler Handler) bool {
 		}
 		return false
 	}
+	if len(data) == 0 {
+		return false
+	}
 
 	switch data[0] {
 	case ComQuit:

go/mysql/mysql_fuzzer_test.go

@@ -24,6 +24,7 @@ import (
 func TestFuzzHandleNextCommand(t *testing.T) {
 	testcases := [][]byte{
 		{0x20, 0x20, 0x20, 0x00, 0x16, 0x20, 0x20, 0x20, 0x20, 0x20},
+		{0x00, 0x00, 0x00, 0x00, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20},
 	}
 	for i, testcase := range testcases {
 		t.Run(strconv.Itoa(i), func(t *testing.T) {