Bug #19894161: FATAL SIGNAL 11 IN

               CONVERT_CHARSET_PARTITION_CONSTANT:
               SQL/SQL_PARTITION..CC:202

Issue:
-----
This problem happens under the following conditions:
1) A table partitioned with a character column as the key.
2) The expressions specified in the partition definition
   requires a charset conversion. This can happen when the
   server's default collation is different from the
   expression's collation.
3) INSERT DELAYED is used to insert data into the table.

SOLUTION:
---------
While creating the delayed_insert object, initialize it
with the relevant select_lex.

sql/sql_insert.cc

@@ -1887,7 +1887,7 @@ public:
   */
   MDL_request grl_protection;
 
-  Delayed_insert()
+  Delayed_insert(SELECT_LEX *current_select)
     :locks_in_memory(0), table(0),tables_in_use(0),stacked_inserts(0),
      status(0), handler_thread_initialized(FALSE), group_count(0)
   {
@@ -1898,7 +1898,7 @@ public:
             USERNAME_LENGTH);
     thd.current_tablenr=0;
     thd.command=COM_DELAYED_INSERT;
-    thd.lex->current_select= 0; 		// for my_message_sql
+    thd.lex->current_select= current_select;
     thd.lex->sql_command= SQLCOM_INSERT;        // For innodb::store_lock()
     /*
       Prevent changes to global.lock_wait_timeout from affecting
@@ -2078,7 +2078,7 @@ bool delayed_get_table(THD *thd, MDL_request *grl_protection_request,
     */
     if (! (di= find_handler(thd, table_list)))
     {
-      if (!(di= new Delayed_insert()))
+      if (!(di= new Delayed_insert(thd->lex->current_select)))
         goto end_create;
       mysql_mutex_lock(&LOCK_thread_count);
       thread_count++;
@@ -2663,6 +2663,16 @@ pthread_handler_t handle_delayed_insert(void *arg)
     if (di->open_and_lock_table())
       goto err;
 
+    /*
+      INSERT DELAYED generally expects thd->lex->current_select to be NULL,
+      since this is not an attribute of the current thread. This can lead to
+      problems if the thread that spawned the current one disconnects.
+      current_select will then point to freed memory. But current_select is
+      required to resolve the partition function. So, after fulfilling that
+      requirement, we set the current_select to 0.
+    */
+    thd->lex->current_select= NULL;
+
     /* Tell client that the thread is initialized */
     mysql_cond_signal(&di->cond_client);