A small step forward. Fixed a few bugs and made string type functions work,

but still strange interferences between multiple function invocations...

mysql-test/r/sp.result

@@ -377,9 +377,10 @@ end;
 drop procedure create_select;
 create function e() returns double
 return 2.7182818284590452354;
-select e();
-e()
-2.718281828459
+set @e = e();
+select e(), @e;
+e()	@e
+2.718281828459	2.718281828459
 create function inc(i int) returns int
 return i+1;
 select inc(1), inc(99), inc(-71);
@@ -390,6 +391,11 @@ return x*y;
 select mul(1,1), mul(3,5), mul(4711, 666);
 mul(1,1)	mul(3,5)	mul(4711, 666)
 1	15	3137526
+create function append(s1 char(8), s2 char(8)) returns char(16)
+return concat(s1, s2);
+select append("foo", "bar");
+append("foo", "bar")
+foobar
 create function fac(n int unsigned) returns bigint unsigned
 begin
 declare f bigint unsigned;
@@ -400,11 +406,12 @@ set n = n - 1;
 end while;
 return f;
 end;
-select fac(1), fac(2), fac(10);
-fac(1)	fac(2)	fac(10)
-1	2	3628800
+select fac(1), fac(2), fac(5), fac(10);
+fac(1)	fac(2)	fac(5)	fac(10)
+1	2	120	3628800
 drop function e;
 drop function inc;
 drop function mul;
+drop function append;
 drop function fac;
 drop table t1;

mysql-test/t/sp.test

@@ -445,7 +445,8 @@ drop procedure create_select|
 create function e() returns double
   return 2.7182818284590452354|
 
-select e()|
+set @e = e()|
+select e(), @e|
 
 # A minimal function with one argument
 create function inc(i int) returns int
@@ -459,6 +460,12 @@ create function mul(x int, y int) returns int
 
 select mul(1,1), mul(3,5), mul(4711, 666)|
 
+# A minimal string function
+create function append(s1 char(8), s2 char(8)) returns char(16)
+  return concat(s1, s2)|
+
+select append("foo", "bar")|
+
 # A function with flow control
 create function fac(n int unsigned) returns bigint unsigned
 begin
@@ -472,11 +479,12 @@ begin
   return f;
 end|
 
-select fac(1), fac(2), fac(10)|
+select fac(1), fac(2), fac(5), fac(10)|
 
 drop function e|
 drop function inc|
 drop function mul|
+drop function append|
 drop function fac|
 
 delimiter ;|

sql/item_func.cc

@@ -2781,44 +2781,42 @@ Item_func_sp::execute(Item **itp)
   DBUG_ENTER("Item_func_sp::execute");
   THD *thd= current_thd;
 
-  if (!m_sp && !(m_sp= sp_find_function(thd, &m_name)))
+  if (! m_sp)
+    m_sp= sp_find_function(thd, &m_name);
+  if (! m_sp)
     DBUG_RETURN(-1);
 
   DBUG_RETURN(m_sp->execute_function(thd, args, arg_count, itp));
 }
 
-Item_result
-Item_func_sp::result_type() const
+enum enum_field_types
+Item_func_sp::field_type() const
 {
-  DBUG_ENTER("Item_func_sp::result_type");
-  DBUG_PRINT("info", ("m_sp = %p", m_sp));
+  DBUG_ENTER("Item_func_sp::field_type");
 
+  if (! m_sp)
+    m_sp= sp_find_function(current_thd, const_cast<LEX_STRING*>(&m_name));
   if (m_sp)
   {
-    DBUG_RETURN(m_sp->result());
-  }
-  else
-  {
-    sp_head *sp= sp_find_function(current_thd, (LEX_STRING *)(&m_name));
-    if (sp)
-      DBUG_RETURN(m_sp->result());
-    DBUG_RETURN(STRING_RESULT);
+    DBUG_PRINT("info", ("m_returns = %d", m_sp->m_returns));
+    DBUG_RETURN(m_sp->m_returns);
   }
+  DBUG_RETURN(MYSQL_TYPE_STRING);
 }
 
-void
-Item_func_sp::make_field(Send_field *field)
+Item_result
+Item_func_sp::result_type() const
 {
-  DBUG_ENTER("Item_func_sp::make_field");
-  Item *it;
+  DBUG_ENTER("Item_func_sp::result_type");
+  DBUG_PRINT("info", ("m_sp = %p", m_sp));
 
-  if (!execute(&it))
+  if (! m_sp)
+    m_sp= sp_find_function(current_thd, const_cast<LEX_STRING*>(&m_name));
+  if (m_sp)
   {
-    it->set_name(name, 0);
-    init_make_field(field, field_type());
-    it->make_field(field);
+    DBUG_RETURN(m_sp->result());
   }
-  DBUG_VOID_RETURN;
+  DBUG_RETURN(STRING_RESULT);
 }
 
 void
@@ -2826,7 +2824,9 @@ Item_func_sp::fix_length_and_dec()
 {
   DBUG_ENTER("Item_func_sp::fix_length_and_dec");
 
-  if (m_sp || (m_sp= sp_find_function(current_thd, &m_name)))
+  if (! m_sp)
+    m_sp= sp_find_function(current_thd, &m_name);
+  if (m_sp)
   {
     switch (m_sp->result()) {
     case STRING_RESULT:

sql/item_func.h

@@ -1161,7 +1161,7 @@ class Item_func_sp :public Item_func
 {
 private:
   LEX_STRING m_name;
-  sp_head *m_sp;
+  mutable sp_head *m_sp;
 
   int execute(Item **itp);
 
@@ -1183,6 +1183,8 @@ class Item_func_sp :public Item_func
     return m_name.str;
   }
 
+  enum enum_field_types field_type() const;
+
   Item_result result_type() const;
 
   longlong val_int()
@@ -1208,8 +1210,6 @@ class Item_func_sp :public Item_func
     return it->val_str(str);
   }
 
-  void make_field(Send_field *field);
-
   void fix_length_and_dec();
 
 };

sql/sp_head.cc

@@ -70,11 +70,11 @@ eval_func_item(THD *thd, Item *it, enum enum_field_types type)
     default:
       {
 	char buffer[MAX_FIELD_WIDTH];
-	String tmp(buffer, sizeof(buffer), default_charset_info);
+	String tmp(buffer, sizeof(buffer), it->charset());
 	String *s= it->val_str(&tmp);
 
-	it= new Item_string(s->c_ptr_quick(), s->length(),
-			    default_charset_info);
+	it= new Item_string(sql_strmake(s->c_ptr_quick(), s->length()),
+			    s->length(), it->charset());
 	break;
       }
     }