Disable multiple_members option for gzip decoder

[ducaale]

Motivation

When decompressing a chunked response with extra bytes like in https://github.com/seanmonstar/reqwest/blob/a2aa5a34e48724be0c1089b0f5afe49b82ece30e/tests/gzip.rs#L306, the client hangs and doesn't return error until the server drops connection.

I think this happens because those extra bytes are treated as the start of another gzip frame.

Solution

We can disable multiple_members and assert that any frames after decompressing body are trailers.

[ducaale]

We need to check if frame is not empty before erroring. See seanmonstar/reqwest#2507 (comment)

[seanmonstar]

@0x676e67 I noticed you filed #548, and while I approved that, I no longer remember why. Seems like we're undoing that here, and perhaps never should have enabled it? I see it is enabled in reqwest for zstd, but all that I remember from gzip, that perhaps is wrong there too?

[0x676e67]

@0x676e67 I noticed you filed #548, and while I approved that, I no longer remember why. Seems like we're undoing that here, and perhaps never should have enabled it? I see it is enabled in reqwest for zstd, but all that I remember from gzip, that perhaps is wrong there too?

@seanmonstar Yes, I remember the context now — it started from these two issues/PRs:
seanmonstar/reqwest#2574
seanmonstar/reqwest#2583

[ducaale]

In that case, I will re-enable multiple_members for zstd. We only need to disable it for gzip to get reqwest tests passing