Bug report

Bug description:

http.client.HTTPResponse doesn't handle negative reads the same as other readers, for example the following code will hang for a significant amount of time:

con = http.client.HTTPConnection("httpbin.org")
con.request("GET", "/get")
resp = con.getresponse()
# "connection: close" doesn't trigger this
assert resp.headers["connection"] == "keep-alive"
while chunk := resp.read(-1):
    print(chunk)

The negative parameter is passed onto the underlying socket which will cause it to try and read to the end-of-stream. For keep-alive connections this just blocks until the connection is closed by the server due to inactivity.

I think this is a bug with not checking for negative amt values in:

Changing the call to read1 causes the above to display the response promptly as I'd expect. This is due to it correctly checking for negative sizes.

Note that in earlier Python versions, e.g. 3.9, the above fails with ValueError: negative count which seems better than timing out, but I think reading to the end of the response makes more sense.

CPython versions tested on:

3.11, 3.12

Operating systems tested on:

Linux

Linked PRs

• gh-112064: fix incorrect handling of negative read sizes in HTTPResponse.read() #128270
• [3.13] gh-112064: Fix incorrect handling of negative read sizes in HTTPResponse.read() (GH-128270) #129395
• [3.12] gh-112064: Fix incorrect handling of negative read sizes in HTTPResponse.read() (GH-128270) #129396