MDEV-20865 FIXMEs

mysql-test/main/foreign_key.result

@@ -241,46 +241,52 @@ test.t3	check	status	OK
 drop tables ch1, t2, t1, t3;
 # Rename column on referenced table
 create or replace table t1 (id int primary key);
-create or replace table t2 (id int references t1);
+create or replace table t2 (id int references t1, id2 int references t1(id));
 select * from t2;
-id
+id	id2
 alter table t1 change id xid int;
 show create table t2;
 Table	Create Table
 t2	CREATE TABLE `t2` (
   `id` int(11) DEFAULT NULL,
+  `id2` int(11) DEFAULT NULL,
   KEY `fk_t2` (`id`),
-  CONSTRAINT `fk_t2` FOREIGN KEY (`id`) REFERENCES `t1` (`xid`)
+  KEY `fk_t2_2` (`id2`),
+  CONSTRAINT `fk_t2` FOREIGN KEY (`id`) REFERENCES `t1` (`xid`),
+  CONSTRAINT `fk_t2_2` FOREIGN KEY (`id2`) REFERENCES `t1` (`xid`)
 ) ENGINE=InnoDB DEFAULT CHARSET=latin1
 select * from t1;
 xid
 check table t2;
 Table	Op	Msg_type	Msg_text
-test.t2	check	Note	Found 1 foreign keys
+test.t2	check	Note	Found 2 foreign keys
 test.t2	check	status	OK
 flush table t2;
 check table t2;
 Table	Op	Msg_type	Msg_text
-test.t2	check	Note	Found 1 foreign keys
+test.t2	check	Note	Found 2 foreign keys
 test.t2	check	status	OK
 alter table t1 rename column xid to yid;
 show create table t2;
 Table	Create Table
 t2	CREATE TABLE `t2` (
   `id` int(11) DEFAULT NULL,
+  `id2` int(11) DEFAULT NULL,
   KEY `fk_t2` (`id`),
-  CONSTRAINT `fk_t2` FOREIGN KEY (`id`) REFERENCES `t1` (`yid`)
+  KEY `fk_t2_2` (`id2`),
+  CONSTRAINT `fk_t2` FOREIGN KEY (`id`) REFERENCES `t1` (`yid`),
+  CONSTRAINT `fk_t2_2` FOREIGN KEY (`id2`) REFERENCES `t1` (`yid`)
 ) ENGINE=InnoDB DEFAULT CHARSET=latin1
 select * from t1;
 yid
 check table t2;
 Table	Op	Msg_type	Msg_text
-test.t2	check	Note	Found 1 foreign keys
+test.t2	check	Note	Found 2 foreign keys
 test.t2	check	status	OK
 flush table t2;
 check table t2;
 Table	Op	Msg_type	Msg_text
-test.t2	check	Note	Found 1 foreign keys
+test.t2	check	Note	Found 2 foreign keys
 test.t2	check	status	OK
 drop tables t2, t1;
 # Check rename table

mysql-test/main/foreign_key.test

@@ -242,7 +242,7 @@ drop tables ch1, t2, t1, t3;
 
 --echo # Rename column on referenced table
 create or replace table t1 (id int primary key);
-create or replace table t2 (id int references t1);
+create or replace table t2 (id int references t1, id2 int references t1(id));
 select * from t2;
 alter table t1 change id xid int;
 show create table t2;

sql/sql_alter.h

@@ -416,7 +416,7 @@ class Alter_table_ctx
     Table_name ref;
     const FK_info *fk;
   };
-  // FIXME: why this stored in std::set?
+  // NB: multiple foreign keys can utilize same column (see fk_prepare_rename())
   mbd::set<FK_rename_col> fk_renamed_cols;
   mbd::set<FK_rename_col> rk_renamed_cols;
   mbd::vector<FK_add_new> fk_added;

sql/unireg.cc

@@ -1546,11 +1546,7 @@ bool TABLE_SHARE::fk_resolve_referenced_keys(THD *thd, TABLE_SHARE *from)
     if (!ids.insert(rk.foreign_id, &inserted))
       return true;
 
-    if (!inserted) // FIXME: assert instead error
-    {
-      my_error(ER_DUP_CONSTRAINT_NAME, MYF(0), "FOREIGN KEY", rk.foreign_id.str);
-      return true;
-    }
+    DBUG_ASSERT(inserted);
   }
 
   for (FK_info &fk: from->foreign_keys)
@@ -1564,8 +1560,9 @@ bool TABLE_SHARE::fk_resolve_referenced_keys(THD *thd, TABLE_SHARE *from)
 
     if (!inserted)
     {
-      my_error(ER_DUP_CONSTRAINT_NAME, MYF(0), "FOREIGN KEY", fk.foreign_id.str);
-      return true; // FIXME: warn instead fail
+      push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN, ER_DUP_CONSTRAINT_NAME,
+                          "Foreign ID already exists `%s`", fk.foreign_id.str);
+      continue;
     }
 
     for (Lex_cstring &fld: fk.referenced_fields)