a fix

(Bug #4035 GROUP_CONCAT with HAVING clause truncates field                       
Bug #4057 LEFT() function in HAVING clause truncates query result).

mysql-test/r/func_gconcat.result

@@ -157,11 +157,8 @@ grp	group_concat(c)
 3	D,D,E
 4	
 5	NULL
-Warnings:
-Warning	1260	1 line(s) was(were) cut by group_concat()
 show warnings;
 Level	Code	Message
-Warning	1260	1 line(s) was(were) cut by group_concat()
 set group_concat_max_len = 1024;
 select group_concat(sum(a)) from t1 group by grp;
 ERROR HY000: Invalid use of group function
@@ -310,3 +307,14 @@ GROUP_CONCAT(t1.a*t2.a ORDER BY t2.a)
 1,2
 2,4
 DROP TABLE t1, t2;
+CREATE TABLE t1 (a char(4));
+INSERT INTO t1 VALUES ('John'), ('Anna'), ('Bill');
+SELECT GROUP_CONCAT(a SEPARATOR '||') AS names FROM t1 
+HAVING names LIKE '%An%';
+names
+John||Anna||Bill
+SELECT GROUP_CONCAT(a SEPARATOR '###') AS names FROM t1 
+HAVING LEFT(names, 1) ='J';
+names
+John###Anna###Bill
+DROP TABLE t1;

mysql-test/t/func_gconcat.test

@@ -189,3 +189,15 @@ INSERT INTO t1 VALUES (1), (2);
 INSERT INTO t2 VALUES (1), (2);
 SELECT GROUP_CONCAT(t1.a*t2.a ORDER BY t2.a) FROM t1, t2 GROUP BY t1.a;
 DROP TABLE t1, t2;
+
+#
+# Bug #4035: group_concat() and HAVING
+#
+
+CREATE TABLE t1 (a char(4));
+INSERT INTO t1 VALUES ('John'), ('Anna'), ('Bill');
+SELECT GROUP_CONCAT(a SEPARATOR '||') AS names FROM t1 
+  HAVING names LIKE '%An%';
+SELECT GROUP_CONCAT(a SEPARATOR '###') AS names FROM t1 
+  HAVING LEFT(names, 1) ='J';
+DROP TABLE t1;

sql/item_strfunc.cc

@@ -950,17 +950,10 @@ String *Item_func_left::val_str(String *str)
     return 0;
   if (length <= 0)
     return &my_empty_string;
-  length= res->charpos(length);
-  if (res->length() > (ulong) length)
-  {						// Safe even if const arg
-    if (!res->alloced_length())
-    {						// Don't change const str
-      str_value= *res;				// Not malloced string
-      res= &str_value;
-    }
-    res->length((uint) length);
-  }
+  if (res->length() <= (uint) length)
     return res;
+  tmp_value.set(*res, 0, res->charpos(length));
+  return &tmp_value;
 }
 
 

sql/item_strfunc.h

@@ -180,6 +180,7 @@ public:
 
 class Item_func_left :public Item_str_func
 {
+  String tmp_value;
 public:
   Item_func_left(Item *a,Item *b) :Item_str_func(a,b) {}
   String *val_str(String *);

sql/item_sum.cc

@@ -1666,6 +1666,9 @@ int dump_leaf_key(byte* key, uint32 count __attribute__((unused)),
   String tmp((char *)&buff,sizeof(buff),default_charset_info), tmp2;
   char *record= (char*) item->table->record[0];
 
+  if (item->result.length())
+    item->result.append(*item->separator);
+
   tmp.length(0);
   
   for (uint i= 0; i < item->arg_count_field; i++)
@@ -1695,14 +1698,6 @@ int dump_leaf_key(byte* key, uint32 count __attribute__((unused)),
         item->result.append(*res);
     }
   }
-  if (item->tree_mode) // Last item of tree
-  {
-    item->show_elements++;
-    if (item->show_elements < item->tree->elements_in_tree)
-      item->result.append(*item->separator);
-  }
-  else
-    item->result.append(*item->separator); 
 
   /* stop if length of result more than group_concat_max_len */  
   if (item->result.length() > item->group_concat_max_len)
@@ -1733,7 +1728,7 @@ Item_func_group_concat::Item_func_group_concat(bool is_distinct,
    tree_mode(0), distinct(is_distinct), warning_for_row(0),
    separator(is_separator), tree(&tree_base), table(0),
    order(0), tables_list(0),
-   show_elements(0), arg_count_order(0), arg_count_field(0),
+   arg_count_order(0), arg_count_field(0),
    count_cut_values(0)
 {
   Item *item_select;
@@ -1799,7 +1794,6 @@ Item_func_group_concat::Item_func_group_concat(THD *thd,
   order(item->order),
   tables_list(item->tables_list),
   group_concat_max_len(item->group_concat_max_len),
-  show_elements(item->show_elements),
   arg_count_order(item->arg_count_order),
   arg_count_field(item->arg_count_field),
   field_list_offset(item->field_list_offset),
@@ -2107,15 +2101,9 @@ String* Item_func_group_concat::val_str(String* str)
     return 0;
   if (tree_mode)
   {
-    show_elements= 0;
     tree_walk(tree, (tree_walk_action)&dump_leaf_key, (void*)this,
               left_root_right);
   }
-  else
-  {
-    if (!warning_for_row)
-      result.length(result.length()-separator->length());
-  }
   if (count_cut_values && !warning_available)
   {
     warning_available= TRUE;

sql/item_sum.h

@@ -694,7 +694,6 @@ class Item_func_group_concat : public Item_sum
   ORDER **order;
   TABLE_LIST *tables_list;
   ulong group_concat_max_len;
-  uint show_elements;
   uint arg_count_order;
   uint arg_count_field;
   uint field_list_offset;