I didn't know it is not acceptable for Sebastian to take my simple hack and improve to an actual patch, instead I appreciate Sebastian's work. If Alexandre believe this is not acceptable, I suggest Sebastian to resend the same patch in his own name while replacing "Based on a patch by Qian Hong." to "Fix a bug spotted by Qian Hong."
I agree that the original work by myself is just a hack, which is just a proof of concept to show the bug, and the final version is already very different to the original one, I think Sebastian is serious to make sure credit my contribution, I appreciate that and I'm really fine if Sebastian resent in his name with the comment I suggested above.