Fix crash in 'INSERT DELAYED' statement that failed due to a

conflict in a unique key. (Bug #12226)

mysql-test/r/delayed.result

@@ -32,3 +32,10 @@ a	b
 3	d
 4	e
 drop table t1;
+create table t1 (a int not null primary key);
+insert into t1 values (1);
+insert delayed into t1 values (1);
+select * from t1;
+a
+1
+drop table t1;

mysql-test/t/delayed.test

@@ -38,3 +38,12 @@ select * from t1;
 drop table t1;
 
 # End of 4.1 tests
+
+#
+# Bug #12226: Crash when a delayed insert fails due to a duplicate key
+#
+create table t1 (a int not null primary key);
+insert into t1 values (1);
+insert delayed into t1 values (1);
+select * from t1;
+drop table t1;

sql/sql_insert.cc

@@ -1088,7 +1088,9 @@ ok_or_after_trg_err:
 
 err:
   info->last_errno= error;
-  thd->lex->current_select->no_error= 0;        // Give error
+  /* current_select is NULL if this is a delayed insert */
+  if (thd->lex->current_select)
+    thd->lex->current_select->no_error= 0;        // Give error
   table->file->print_error(error,MYF(0));
 
 before_trg_err: