Difference in affected row count in MySQL 9.1 vs MariaDB 13.1 on ALTER VARCHAR

--source include/have_innodb.inc

CREATE TABLE t (c VARCHAR(16)) ENGINE=InnoDB;

INSERT INTO t VALUES('v0');

ALTER TABLE t CHANGE c c_renamed VARCHAR(168) FIRST;

DROP TABLE IF EXISTS t;

9.1.0-opt>ALTER TABLE t3 CHANGE c2 c2_renamed VARCHAR(168) FIRST;

Query OK, 1 row affected (0.03 sec)

Records: 1  Duplicates: 0  Warnings: 0

13.1.0-opt>ALTER TABLE t3 CHANGE c2 c2_renamed VARCHAR(168) FIRST;

Query OK, 0 rows affected (0.007 sec)

Records: 0  Duplicates: 0  Warnings: 0

    Rel    o/d  Build   Commit                                    Diff observed

ES  10.6   dbg  180826  fcecb2620f25965723d640decede7c018bcb1dcc  DIFF: AFFECTED ROWS

ES  10.6   opt  180826  fcecb2620f25965723d640decede7c018bcb1dcc  DIFF: AFFECTED ROWS

ES  11.4   dbg  180826  3b34189bfe675c18c4ced3ef531d016ea74c76f4  DIFF: AFFECTED ROWS

ES  11.4   opt  180826  3b34189bfe675c18c4ced3ef531d016ea74c76f4  DIFF: AFFECTED ROWS

ES  11.8   dbg  180826  4694e931d10fecf733c34f83ea2146d31b708eb3  DIFF: AFFECTED ROWS

ES  11.8   opt  180826  4694e931d10fecf733c34f83ea2146d31b708eb3  DIFF: AFFECTED ROWS

ES  12.3   dbg  180826  f513f503feacabfb219d4a6f965b5f72b86d4db0  DIFF: AFFECTED ROWS

ES  12.3   opt  180826  f513f503feacabfb219d4a6f965b5f72b86d4db0  DIFF: AFFECTED ROWS

CS  10.11  dbg  180826  8f00e6caca633c783140db86d3a48a96de67cf38  DIFF: AFFECTED ROWS

CS  10.11  opt  180826  8f00e6caca633c783140db86d3a48a96de67cf38  DIFF: AFFECTED ROWS

CS  11.4   dbg  180826  1a052f27e374fc9b4cb5b1fd098cf10f0e1381cc  DIFF: AFFECTED ROWS

CS  11.4   opt  180826  1a052f27e374fc9b4cb5b1fd098cf10f0e1381cc  DIFF: AFFECTED ROWS

CS  11.8   dbg  180826  d26f9ab217a7fcf9d4eccc62c01020ff275ff42e  DIFF: AFFECTED ROWS

CS  11.8   opt  180826  d26f9ab217a7fcf9d4eccc62c01020ff275ff42e  DIFF: AFFECTED ROWS

CS  12.3   dbg  180826  add63991988734383c5e942de2a19c6c45f511f7  DIFF: AFFECTED ROWS

CS  12.3   opt  180826  add63991988734383c5e942de2a19c6c45f511f7  DIFF: AFFECTED ROWS

CS  13.0   dbg  180826  a848493c6fe031f23606144420c1ca1e467cbd81  DIFF: AFFECTED ROWS

CS  13.0   opt  180826  a848493c6fe031f23606144420c1ca1e467cbd81  DIFF: AFFECTED ROWS

CS  13.1   dbg  180826  da18481158c81ca94689702073c3e04aad85a6a3  DIFF: AFFECTED ROWS

CS  13.1   opt  180826  da18481158c81ca94689702073c3e04aad85a6a3  DIFF: AFFECTED ROWS

MS  8.0    dbg  060224  49ef33f7edadef3ae04665e73d1babd40179a4f1  Same as base/source

MS  8.0    opt  060224  49ef33f7edadef3ae04665e73d1babd40179a4f1  Same as base/source

MS  5.5    dbg  070123  bac287c315b1792e7ae33f91add6a60292f9bae8  Same as base/source

MS  5.5    opt  070123  bac287c315b1792e7ae33f91add6a60292f9bae8  Same as base/source

MS  5.6    dbg  070123  dab95781a1244104d6b87020ac2fc4d190ba2946  Same as base/source

MS  5.6    opt  070123  dab95781a1244104d6b87020ac2fc4d190ba2946  Same as base/source

MS  5.7    dbg  070525  f7680e98b6bbe3500399fbad465d08a6b75d7a5c  Same as base/source

MS  5.7    opt  070525  f7680e98b6bbe3500399fbad465d08a6b75d7a5c  Same as base/source

MS  9.1    dbg  211024  61a3a1d8ef15512396b4c2af46e922a19bf2b174  Same as base/source

MS  9.1    opt  211024  61a3a1d8ef15512396b4c2af46e922a19bf2b174  BASE/SOURCE