SimplePie 1.x

Patched on the trunk @ r968, although I'd like it to get more testing before pushing it out to the branch.

We can't use stuff from the PHP manual, and the license is incompatible. I was working on code for this before, anyway. And blaming IIS/6.0 is wrong. It's us who doesn't comply with the spec.

To quote Wikipedia's gzip page:

The “Content-Encoding” header in HTTP/1.1 allows clients to optionally receive compressed HTTP responses and (less commonly) to send compressed requests. The standard itself specifies two compression methods: “gzip” (RFC 1952; the content wrapped in a gzip stream) and “deflate” (RFC 1950; the content wrapped in a zlib-formatted stream). Compressed responses are supported by many HTTP client libraries, almost all modern browsers and both of the major HTTP server platforms, Apache and Microsoft IIS. Many server implementations, however, incorrectly implement the protocol by using the raw DEFLATE stream format (RFC 1951) instead. The bug is sufficiently pervasive that most modern browsers will accept both RFC 1951 and RFC 1950-formatted data for the “deflate” compressed method.

PHP < 6 has no built in function to read Gzip streams (it is gzdecode(), FWIW, but it gives no access to any of the metadata). This does that on PHP 5, and should be easily portable to PHP 4. gzuncompress() deals with Zlib streams (the "deflate" type in HTTP/1.1), and gzinflate() deals with raw DEFLATE streams.

For Content-Encoding: gzip, we should use gzdecode() or my class; and for Content-Encoding: deflate, we should try gzuncompress(), but fallback to gzinflate().

Oh, and reopening it.

Applied in changeset r1011.

Re-opening for 1.1.2.

Applied in changeset r1017.

Still broken; unpack doesn't return unsigned ints (see note at http://de3.php.net/unpack), so you need to do the following:

$crc = current(unpack('N', substr($this->compressed_data, $this->position, 4)));
if ($crc < 0) {
$crc += 4294967296;
}

Yet ISIZE is not decoded correctly, don't know what's wrong there.

Adrian Lang wrote:

Still broken; unpack doesn't return unsigned ints (see note at http://de3.php.net/unpack), so you need to do the following:

$crc = current(unpack('N', substr($this->compressed_data, $this->position, 4))); if ($crc < 0) { $crc += 4294967296; }

Yet ISIZE is not decoded correctly, don't know what's wrong there.

CRC shouldn't be a problem: both unpack and hexdec will return signed integers and not unsigned, but comparing these still works as they are still bit-for-bit equivalent (expect, maybe, on 64-bit systems?). That work around doesn't work on 32-bit systems. Regardless, this should be a separate ticket.