InnoDB ALTER TABLE treats auto_increment_increment,auto_increment_offset differently from ALGORITHM=COPY

The fix of Bug#14219624 - ALTER TABLE...ADD COL AUTO_INCREMENT DOES NOT OBEY AUTO_INCREMENT_OFFSET was incomplete. Contrary to what is claimed in the test innodb.innodb-alter-autoinc, the results do differ between ALGORITHM=COPY and ALGORITHM=INPLACE. Here is an example:

git checkout origin/10.1

diff -u <(tail +76 mysql-test/suite/innodb/r/innodb-alter-autoinc.result|head) --label COPY <(tail +156 mysql-test/suite/innodb/r/innodb-alter-autoinc.result|head) --label INPLACE

--- COPY

+++ INPLACE

@@ -6,5 +6,5 @@

 123	55

 347	60

 33101	65

-123	70

 123	75

+123	80

This could cause corruption in replication or in Galera cluster, especially if only some nodes are using old_alter_table=1, or some are running a server version where the ALTER TABLE operation is executed using a different ALGORITHM.