Hello all, inspecting the CompressionFilter change, introduced in 2.2.8, it seems that there crept in a cut and paste error in the initialisation of the Zlib used for deflate. It is literally the same initialization as for the inflate. See: https://github.com/apache/mina/blob/2.2.X/mina-filter-compression/src/main/java/org/apache/mina/filter/compression/CompressionFilter.java#L280
In 2.2.7 is the inflate Zlib initialized with Zlib.MODE_INFLATER and the deflate with Zlib.MODE_DEFLATE. In 2.2.8 are both with Zlib.MODE_INFLATER. I do not think that this is the intention. Same on 2.0.x and 2.1.x branches. Regards Jörg
