Bug#20777 Function w BIGINT UNSIGNED shows diff. behaviour with and without --ps-protocol

- Stored procedures returning unsinged values returns signed values if
  text protocol is used. The reason is that the stored proceedure item
  Item_func_sp wasn't initializing the member variables properly based
  on the information contained in the associated result field.
- The patch is to upon field-item association, ::fix_fields, initialize
  the member variables in appropriate order.
- Field type of an Item_func_sp was hard coded to MYSQL_TYPE_VARCHAR.
  This is changed to return the type of the actual result field.
- Member function name sp_result_field was refactored to the more 
  appropriate init_result_field.
- Member function name find_and_check_access was refactored to 
  sp_check_access.


mysql-test/r/sp.result:
  - Added test
mysql-test/t/sp.test:
  - Added test
sql/item_func.cc:
  Bug#20777 Function w BIGINT UNSIGNED shows diff. behaviour with and without --ps-protocol
  
  - Stored procedures returning unsinged values returns signed values if
    text protocol is used. The reason is that the stored proceedure item
    Item_func_sp wasn't initializing the member variables properly based
    on the information contained in the associated result field.
  - The patch is to upon field-item association, ::fix_fields, initialize
    the member variables in appropriate order.
  - Field type of an Item_func_sp was hard coded to MYSQL_TYPE_VARCHAR.
    This is changed to to return the type of the actual result field.
  - Member function name sp_result_field was refactored to the more 
    appropriate init_result_field.
  - Member function name find_and_check_access was refactored to 
    sp_check_access.
sql/item_func.h:
  Bug#20777 Function w BIGINT UNSIGNED shows diff. behaviour with and without --ps-protocol
  
  - Stored procedures returning unsinged values returns signed values if
    text protocol is used. The reason is that the stored proceedure item
    Item_func_sp wasn't initializing the member variables properly based
    on the information contained in the associated result field.
  - The patch is to upon field-item association, ::fix_fields, initialize
    the member variables in appropriate order.
  - Field type of an Item_func_sp was hard coded to MYSQL_TYPE_VARCHAR.
    This is changed to to return the type of the actual result field.
  - Member function name sp_result_field was refactored to the more 
    appropriate init_result_field.
  - Member function name find_and_check_access was refactored to 
    sp_check_access.

1 files changed, 17 insertions, 14 deletions

diff --git a/sql/item_func.h b/sql/item_func.h
index 68591f9c6f5..6a619327590 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -1405,12 +1405,15 @@ private:
   sp_name *m_name;
   mutable sp_head *m_sp;
   TABLE *dummy_table;
-  Field *result_field;
   char result_buf[64];
+  /*
+     The result field of the concrete stored function.
+  */
+  Field *sp_result_field;
 
-  bool execute(Field **flp);
-  bool execute_impl(THD *thd, Field *return_value_fld);
-  Field *sp_result_field(void) const;
+  bool execute();
+  bool execute_impl(THD *thd);
+  bool init_result_field(THD *thd);
 
 public:
 
@@ -1436,23 +1439,23 @@ public:
 
   longlong val_int()
   {
-    if (execute(&result_field))
+    if (execute())
       return (longlong) 0;
-    return result_field->val_int();
+    return sp_result_field->val_int();
   }
 
   double val_real()
   {
-    if (execute(&result_field))
+    if (execute())
       return 0.0;
-    return result_field->val_real();
+    return sp_result_field->val_real();
   }
 
   my_decimal *val_decimal(my_decimal *dec_buf)
   {
-    if (execute(&result_field))
+    if (execute())
       return NULL;
-    return result_field->val_decimal(dec_buf);
+    return sp_result_field->val_decimal(dec_buf);
   }
 
   String *val_str(String *str)
@@ -1461,7 +1464,7 @@ public:
     char buff[20];
     buf.set(buff, 20, str->charset());
     buf.length(0);
-    if (execute(&result_field))
+    if (execute())
       return NULL;
     /*
       result_field will set buf pointing to internal buffer
@@ -1469,7 +1472,7 @@ public:
       when SP is executed. In order to prevent occasional
       corruption of returned value, we make here a copy.
     */
-    result_field->val_str(&buf);
+    sp_result_field->val_str(&buf);
     str->copy(buf);
     return str;
   }
@@ -1477,11 +1480,11 @@ public:
   virtual bool change_context_processor(byte *cntx)
     { context= (Name_resolution_context *)cntx; return FALSE; }
 
-  void fix_length_and_dec();
-  bool find_and_check_access(THD * thd);
+  bool sp_check_access(THD * thd);
   virtual enum Functype functype() const { return FUNC_SP; }
 
   bool fix_fields(THD *thd, Item **ref);
+  void fix_length_and_dec(void);
   bool is_expensive() { return 1; }
 };