Use streaming decompress to identify extent of compressed data. #66
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This fixes a problem that arises for local files with bit 3 of the general purpose bit flag set. In this case, we don't get information up front about the size of the compressed data. So how do we know where the compressed data ends? Previously, we tried to determine this by looking for the signature of the data descriptor. But this doesn't always HAVE a signature, and it is also possible for signatures to occur accidentally in the compressed data itself. Here we follow a clue from an Info-ZIP note: "In general, this feature can only be reliably used together with compression methods that allow intrinsic detection of the 'end-of-compressed-data' condition." We use the streaming decompression interface from zlib's Internal module. This tells us, in effect, where the compressed data ends. Closes #65.
We need to handle cases where there is no compression.
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This fixes a problem that arises for local files with bit 3 of the general purpose bit flag set. In this case, we don't get information up front about the size of the compressed data. So how do we know where the compressed data ends? Previously, we tried to determine this by looking for the signature of the data descriptor. But this doesn't always HAVE a signature, and it is also possible for signatures to occur accidentally in the compressed data itself.
Here we follow a clue from an Info-ZIP note:
"In general, this feature can only be reliably used together with compression methods that allow intrinsic detection of the 'end-of-compressed-data' condition."
We use the streaming decompression interface from
zlib's Internal module. This tells us, in effect, where the compressed data ends.
Closes #65.