A fix for a crashing bug #7101, which occures when the

expression involving LEFT() function is used in GROUP BY
field.


mysql-test/r/func_str.result:
  A result for bug #7101 test case
mysql-test/t/func_str.test:
  Test case for bug #7101

2 files changed, 4 insertions, 2 deletions

diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index 893126b7fe6..7fc5e51621e 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -955,8 +955,9 @@ String *Item_func_left::val_str(String *str)
   if (res->length() <= (uint) length ||
       res->length() <= (char_pos= res->charpos(length)))
     return res;
-  str_value.set(*res, 0, char_pos);
-  return &str_value;
+
+  tmp_value.set(*res, 0, char_pos);
+  return &tmp_value;
 }
 
 
diff --git a/sql/item_strfunc.h b/sql/item_strfunc.h
index afe03c31345..8efe60bbd89 100644
--- a/sql/item_strfunc.h
+++ b/sql/item_strfunc.h
@@ -162,6 +162,7 @@ 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 *);