Before MariaDB 10.3.5, the binlog position was stored in the TRX_SYS page,
while after it is stored in rollback segments. There is code to read the
legacy position from TRX_SYS to handle upgrades. The problem was if the
legacy position happens to compare larger than the position found in
rollback segments; in this case, the old TRX_SYS position would incorrectly
be preferred over the newer position from rollback segments.
Fixed by always preferring a position from rollback segments over a legacy
position.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Write a test case that computes valid crc32 checksums for
an encrypted page, but zeroes out the payload area, so
that the checksum after decryption fails.
xb_fil_cur_read(): Validate the page number before trying
any checksum calculation or decrypting or decompression.
Also, skip zero-filled pages. For page_compressed pages,
ensure that the FIL_PAGE_TYPE was changed. Also, reject
FIL_PAGE_PAGE_COMPRESSED_ENCRYPTED if no decryption was attempted.