BUG

correct bug 1085 (a problem with min/max functions)
add tests of bugs 833,836,1085


mysql-test/r/func_gconcat.result:
  add tests of bugs 833, 836, 1085
mysql-test/t/func_gconcat.test:
  add tests of bugs #833, 836, 1085
sql/item_sum.cc:
  merge
sql/item_sum.h:
  correct bug 1085

mysql-test/r/func_gconcat.result

@@ -167,6 +167,11 @@ t2.URL_ID = t1.URL_ID group by REQ_ID;
 REQ_ID	URL
 1	X
 5	X,X,X
+select REQ_ID, Group_Concat(URL) as URL, Min(t1.URL_ID) urll,
+Max(t1.URL_ID)
 urlg from t1, t2 where t2.URL_ID = t1.URL_ID group by REQ_ID;
+REQ_ID	URL	urll	urlg
+1	X	4	4
+5	X,X,X	4	5
 drop table t1;
 drop table t2;
 create table t1 (id int, name varchar(16));
@@ -178,3 +183,16 @@ select distinct ifnull(group_concat(concat(t1.id, ':', t1.name)), 'shortname') a
 with distinct: cutoff at length of shortname
 1:longername,1:evenlongername
 drop table t1;
+create table t1(id int);
+create table t2(id int);
+insert into t1 values(0),(1);
+select group_concat(t1.id) FROM t1,t2;
+group_concat(t1.id)
+NULL
+drop table t1;
+drop table t2;
+create table t1 (bar varchar(32));
+insert into t1 values('test'),('test2');
+select * from t1 having group_concat(bar)='';
+bar
+drop table t1;

mysql-test/t/func_gconcat.test

@@ -91,6 +91,11 @@ insert into t2 values (1,4), (5,4), (5,5);
 --replace_result www.help.com X www.host.com X www.google.com X
 select REQ_ID, Group_Concat(URL) as URL from t1, t2 where 
 t2.URL_ID = t1.URL_ID group by REQ_ID;
+# check min/max function
+--replace_result www.help.com X www.host.com X www.google.com X
+select REQ_ID, Group_Concat(URL) as URL, Min(t1.URL_ID) urll,
+Max(t1.URL_ID)
 urlg from t1, t2 where t2.URL_ID = t1.URL_ID group by REQ_ID;
+
 drop table t1;
 drop table t2;
 
@@ -99,3 +104,19 @@ insert into t1 values (1,'longername'),(1,'evenlongername');
 select ifnull(group_concat(concat(t1.id, ':', t1.name)), 'shortname') as 'without distinct: how it should be' from t1;
 select distinct ifnull(group_concat(concat(t1.id, ':', t1.name)), 'shortname') as 'with distinct: cutoff at length of shortname' from t1;
 drop table t1;
+
+# check zero rows
+create table t1(id int);
+create table t2(id int);
+insert into t1 values(0),(1);
+select group_concat(t1.id) FROM t1,t2;
+drop table t1;
+drop table t2;
+
+# check having
+create table t1 (bar varchar(32));
+insert into t1 values('test'),('test2');
+select * from t1 having group_concat(bar)='';
+drop table t1;
+
+

sql/item_sum.cc

@@ -1460,7 +1460,7 @@ int group_concat_key_cmp_with_distinct(void* arg, byte* key1,
   for (uint i= 0; i < item->arg_count_field; i++)
   {
     Item *field_item= item->args[i];
-    Field *field= field_item->real_item()->tmp_table_field();
+    Field *field= field_item->real_item()->get_tmp_table_field();
     if (field)
     {
       uint offset= field->abs_offset;
@@ -1491,7 +1491,7 @@ int group_concat_key_cmp_with_order(void* arg, byte* key1, byte* key2)
   {
     ORDER *order_item= item->order[i];
     Item *item= *order_item->item;
-    Field *field= item->real_item()->tmp_table_field();
+    Field *field= item->real_item()->get_tmp_table_field();
     if (field)
     {
       uint offset= field->abs_offset;
@@ -1542,7 +1542,7 @@ int dump_leaf_key(byte* key, uint32 count __attribute__((unused)),
     Item *show_item= group_concat_item->args[i];
     if (!show_item->const_item())
     {
-      Field *f= show_item->real_item()->tmp_table_field();
+      Field *f= show_item->real_item()->get_tmp_table_field();
       char *sv= f->ptr;
       f->ptr= (char *)key + f->abs_offset;
       String *res= f->val_str(&tmp,&tmp2);
@@ -1709,7 +1709,7 @@ bool Item_func_group_concat::add()
     Item *show_item= args[i];
     if (!show_item->const_item())
     {
-      Field *f= show_item->real_item()->tmp_table_field();
+      Field *f= show_item->real_item()->get_tmp_table_field();
       if (!f->is_null())
       {
         record_is_null= FALSE;      

sql/item_sum.h

@@ -386,8 +386,8 @@ class Item_sum_hybrid :public Item_sum
   Item_sum_hybrid(THD *thd, Item_sum_hybrid &item):
     Item_sum(thd, item), value(item.value), tmp_value(item.tmp_value),
     sum(item.sum), sum_int(item.sum_int), hybrid_type(item.hybrid_type),
-    cmp_sign(item.cmp_sign), used_table_cache(used_table_cache),
-    cmp_charset(item.cmp_charset) {}
+    hybrid_field_type(item.hybrid_field_type),cmp_sign(item.cmp_sign), 
+    used_table_cache(used_table_cache), cmp_charset(item.cmp_charset) {}
   bool fix_fields(THD *, TABLE_LIST *, Item **);
   table_map used_tables() const { return used_table_cache; }
   bool const_item() const { return !used_table_cache; }