An HTTP2 DataFrame with pad_length=0 returns no payload

[mattfysh]

Describe the bug
An HTTP2 DataFrame with pad_length=0 returns no payload

To Reproduce
When unpacking a PaddedFrame with HTTP2_FLAG_PADDED, zero is a valid pad_length, however the calculation of the payload occurs using:

self.unpadded_data = self.data[1:-self.pad_length]

if pad_length is zero, this wipes out the frame's data

Expected behavior

self.unpadded_data = self.data[1:] if self.pad_length == 0 else self.data[1:-self.pad_length]

Details(please complete the following information):

• OS: MacOS
• Python Version 3.21