[#MDEV-15937] Assertion failure 'key->flags & 1' on ALTER TABLE

CREATE TABLE t1(c1 INT) ENGINE=InnoDB;

ALTER TABLE t1 ADD CONSTRAINT UNIQUE KEY i1(c1);

ALTER TABLE t1 CHANGE c1 c1 INT NOT NULL,ADD KEY(c1);

DROP TABLE t1;

There is a fix for this in MySQL 8.0.11, but I think that we should fix this differently in MariaDB, and starting from the first potentially affected version (10.0). I was not able to repeat a failure on 10.0 even after adding a debug assertion.

diff --git a/storage/innobase/handler/handler0alter.cc b/storage/innobase/handler/handler0alter.cc

index 02a8428cdc9..20bac687ccf 100644

--- a/storage/innobase/handler/handler0alter.cc

+++ b/storage/innobase/handler/handler0alter.cc

@@ -2597,10 +2597,8 @@ innobase_create_key_defs(

 				DBUG_ASSERT(got_default_clust);

 				DBUG_ASSERT(altered_table->s->primary_key

 					    == 0);

-				primary_key_number = 0;

-			} else {

-				primary_key_number = *add;

+			primary_key_number = altered_table->s->primary_key;

 		} else if (got_default_clust) {

 			/* Create the GEN_CLUST_INDEX */

 			index_def_t*	index = indexdef++;

[MDEV-15937] Assertion failure 'key->flags & 1' on ALTER TABLE Created: 2018-04-20 Updated: 2018-04-23 Resolved: 2018-04-23
Status:	Closed
Project:	MariaDB Server
Component/s:	Storage Engine - InnoDB
Affects Version/s:	10.2.2, 10.3.0
Fix Version/s:	10.0.35, 10.1.33, 10.2.15, 10.3.7

[MDEV-15937] Assertion failure 'key->flags & 1' on ALTER TABLE Created: 2018-04-20 Updated: 2018-04-23 Resolved: 2018-04-23