Fix for MDEV-14141 Crash in print_keydup_error()

May also fix: MDEV-14970 "MariaDB crashed with signal 11 and Aria table"

I am not able to reproduce a crash, however there was no protection in
print_keydup_error() if the storage engine reported the wrong key number.

This patch adds such a protection and should stop any further crashes
in this case.

Other things:
- Added extra protection in Aria to not set errkey to more than number of
  keys. (Don't think this is cause of this crash, but better safe than
  sorry)
- Extend test_if_equal_repl_errors() to handle different cases of
  ER_DUP_ENTRY. This is just mainly precaution for the future.

1 files changed, 2 insertions, 2 deletions

diff --git a/mysql-test/r/merge.result b/mysql-test/r/merge.result
index 31edbc0fdce..14308959557 100644
--- a/mysql-test/r/merge.result
+++ b/mysql-test/r/merge.result
@@ -2167,7 +2167,7 @@ col1 int(10) NOT NULL
 ) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=LAST UNION=(t1);
 insert into m1 (col1) values (1);
 insert into m1 (col1) values (1);
-ERROR 23000: Duplicate entry '' for key '*UNKNOWN*'
+ERROR 23000: Can't write; duplicate key in table 'm1'
 drop table m1, t1;
 #
 # Bug#45800 crash when replacing into a merge table and there is a duplicate
@@ -2204,7 +2204,7 @@ CREATE TABLE m1 (c1 INT, c2 INT, UNIQUE (c1)) ENGINE=MRG_MyISAM INSERT_METHOD=LA
 INSERT INTO m1 VALUES (1,2);
 # insert the duplicate value into the merge table
 INSERT INTO m1 VALUES (3,2);
-ERROR 23000: Duplicate entry '' for key '*UNKNOWN*'
+ERROR 23000: Can't write; duplicate key in table 'm1'
 DROP TABLE m1,t1;
 # Try to define MERGE and MyISAM with keys on different columns
 CREATE TABLE t1 (c1 INT, c2 INT, UNIQUE (c1));