Make sure that warning message when GROUP_CONCAT() cuts values is also

updated with the correct number of lines. (Bug #8681)


mysql-test/t/join_outer.test:
  Add new regression test
mysql-test/r/join_outer.result:
  Add new results
sql/item_sum.cc:
  Move cleanup of warning message outside of "if (original)" test or it won't
  always get cleaned up.

mysql-test/r/join_outer.result

@@ -816,3 +816,22 @@ id	text_id	text_data
 1	0	0-SV
 2	10	10-SV
 DROP TABLE invoice, text_table;
+set group_concat_max_len=5;
+create table t1 (a int, b varchar(20));
+create table t2 (a int, c varchar(20));
+insert into t1 values (1,"aaaaaaaaaa"),(2,"bbbbbbbbbb");
+insert into t2 values (1,"cccccccccc"),(2,"dddddddddd");
+select group_concat(t1.b,t2.c) from t1 left join t2 using(a) group by t1.a;
+group_concat(t1.b,t2.c)
+aaaaa
+bbbbb
+Warnings:
+Warning	1260	2 line(s) were cut by GROUP_CONCAT()
+select group_concat(t1.b,t2.c) from t1 inner join t2 using(a) group by t1.a;
+group_concat(t1.b,t2.c)
+aaaaa
+bbbbb
+Warnings:
+Warning	1260	2 line(s) were cut by GROUP_CONCAT()
+drop table t1, t2;
+set group_concat_max_len=default;

mysql-test/t/join_outer.test

@@ -582,3 +582,14 @@ SELECT invoice.id, invoice.text_id, text_table.text_data
   WHERE (invoice.id LIKE '%' OR text_table.text_data LIKE '%');
 
 DROP TABLE invoice, text_table;
+
+# Bug #8681: Bad warning message when group_concat() exceeds max length
+set group_concat_max_len=5;
+create table t1 (a int, b varchar(20));
+create table t2 (a int, c varchar(20));
+insert into t1 values (1,"aaaaaaaaaa"),(2,"bbbbbbbbbb");
+insert into t2 values (1,"cccccccccc"),(2,"dddddddddd");
+select group_concat(t1.b,t2.c) from t1 left join t2 using(a) group by t1.a;
+select group_concat(t1.b,t2.c) from t1 inner join t2 using(a) group by t1.a;
+drop table t1, t2;
+set group_concat_max_len=default;

sql/item_sum.cc

@@ -1787,16 +1787,26 @@ Item_func_group_concat::Item_func_group_concat(THD *thd,
 
 void Item_func_group_concat::cleanup()
 {
+  THD *thd= current_thd;
+
   DBUG_ENTER("Item_func_group_concat::cleanup");
   Item_sum::cleanup();
 
+  /* Adjust warning message to include total number of cut values */
+  if (warning)
+  {
+    char warn_buff[MYSQL_ERRMSG_SIZE];
+    sprintf(warn_buff, ER(ER_CUT_VALUE_GROUP_CONCAT), count_cut_values);
+    warning->set_msg(thd, warn_buff);
+    warning= 0;
+  }
+
   /*
     Free table and tree if they belong to this item (if item have not pointer
     to original item from which was made copy => it own its objects )
   */
   if (!original)
   {
-    THD *thd= current_thd;
     if (table)
     {
       free_tmp_table(thd, table);
@@ -1809,13 +1819,6 @@ void Item_func_group_concat::cleanup()
       tree_mode= 0;
       delete_tree(tree); 
     }
-    if (warning)
-    {
-      char warn_buff[MYSQL_ERRMSG_SIZE];
-      sprintf(warn_buff, ER(ER_CUT_VALUE_GROUP_CONCAT), count_cut_values);
-      warning->set_msg(thd, warn_buff);
-      warning= 0;
-    }
   }
   DBUG_VOID_RETURN;
 }
@@ -2076,6 +2079,10 @@ String* Item_func_group_concat::val_str(String* str)
   if (null_value)
     return 0;
   if (count_cut_values && !warning)
+    /*
+      ER_CUT_VALUE_GROUP_CONCAT needs an argument, but this gets set in
+      Item_func_group_concat::cleanup().
+    */
     warning= push_warning(item_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
                           ER_CUT_VALUE_GROUP_CONCAT,
                           ER(ER_CUT_VALUE_GROUP_CONCAT));