In commit 437da7bc54 (MDEV-19534),
the default value of the global variable srv_checksum_algorithm
in innochecksum was changed from SRV_CHECKSUM_ALGORITHM_INNODB
to implied 0 (innodb_checksum_algorithm=crc32). As a result,
the function buf_page_is_corrupted() would by default invoke
buf_calc_page_crc32() in innochecksum, and crc32_inited would hold.
This would cause "innochecksum" to fail on a particular page.
The actual problem is older, introduced in 2011 in
mysql/mysql-server@17e497bdb7
(MySQL 5.6.3). It should affect the validation of pages of old
data files that were written with innodb_checksum_algorithm=innodb.
When using innodb_checksum_algorithm=crc32 (the default setting
since MariaDB Server 10.2), some valid pages would be rejected
only because exactly one of the two checksum fields accidentally
matches the innodb_checksum_algorithm=crc32 value.
buf_page_is_corrupted(): Simplify the logic of non-strict
checksum validation, by always invoking buf_calc_page_crc32().
Remove a bogus condition that if only one of the checksum fields
contains the value returned by buf_calc_page_crc32(), the page
is corrupted.
303448bc91