A 32-bit server build has a limitation of 2^32 bytes max for IO_CACHE.
This is quite a reachable value for a single transaction.

If DML reaches it, and the engine is not rollback-capable, then the last
record operation will be lost after ALTER TABLE.

To avoid it, report the error to the ALTER TABLE side and ignore it on the
DML side. Thus, a DML will not fail because of an online alter log failure.