When testing the 3.1-RC1 made by Yonik on the PANGAEA (www.pangaea.de) productive system I figured out that suddenly on a large segment (about 5 GiB) some stored fiels suddenly produce a strange deflate decompression problem (CompressionTools) although the stored fields are no longer pre-3.0 compressed. It seems that the header of the stored field is read incorrectly at the buffer boundary in MultiMMapDir and then FieldsReader just incorrectly detects a deflate-compressed field (CompressionTools).
The error occurs reproducible on CheckIndex with MMapDirectory, but not with NIODir or SimpleDir. The FDT file of that segment is 2.6 GiB, on Solaris the chunk size is Integer.MAX_VALUE, so we have 2 MultiMMap IndexInputs.
Robert and me have the index ready as a tar file, we will do tests on our local machines and hopefully solve the bug, maybe introduced by Robert's recent changes to MMap.