1 files changed, 137 insertions, 106 deletions

diff --git a/sql/item_func.cc b/sql/item_func.cc
index 0f9ee512be1..bc7c95d8929 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -2105,13 +2105,13 @@ bool Item_func_set_user_var::fix_fields(THD *thd, TABLE_LIST *tables,
   if (Item_func::fix_fields(thd, tables, ref) ||
       !(entry= get_variable(&thd->user_vars, name, 1)))
     return 1;
-  entry->type= cached_result_type;
   /* 
      Remember the last query which updated it, this way a query can later know
      if this variable is a constant item in the query (it is if update_query_id
      is different from query_id).
   */
-  entry->update_query_id=thd->query_id;
+  entry->update_query_id= thd->query_id;
+  cached_result_type= args[0]->result_type();
   return 0;
 }
 
@@ -2122,10 +2122,10 @@ Item_func_set_user_var::fix_length_and_dec()
   maybe_null=args[0]->maybe_null;
   max_length=args[0]->max_length;
   decimals=args[0]->decimals;
-  cached_result_type=args[0]->result_type();
 }
 
-void Item_func_set_user_var::update_hash(void *ptr, uint length,
+
+bool Item_func_set_user_var::update_hash(void *ptr, uint length,
 					 Item_result type,
 					 CHARSET_INFO *cs,
 					 Derivation dv)
@@ -2141,6 +2141,8 @@ void Item_func_set_user_var::update_hash(void *ptr, uint length,
   }
   else
   {
+    if (type == STRING_RESULT)
+      length++;					// Store strings with end \0
     if (length <= extra_size)
     {
       /* Save value in value struct */
@@ -2165,35 +2167,135 @@ void Item_func_set_user_var::update_hash(void *ptr, uint length,
 	  goto err;
       }
     }
+    if (type == STRING_RESULT)
+    {
+      length--;					// Fix length change above
+      entry->value[length]= 0;			// Store end \0
+    }
     memcpy(entry->value,ptr,length);
     entry->length= length;
     entry->type=type;
     entry->collation.set(cs, dv);
   }
-  return;
+  return 0;
 
  err:
   current_thd->fatal_error();			// Probably end of memory
-  null_value=1;
-  return;
+  null_value= 1;
+  return 1;
+}
+
+
+/* Get the value of a variable as a double */
+
+double user_var_entry::val(my_bool *null_value)
+{
+  if ((*null_value= (value == 0)))
+    return 0.0;
+
+  switch (type) {
+  case REAL_RESULT:
+    return *(double*) value;
+  case INT_RESULT:
+    return (double) *(longlong*) value;
+  case STRING_RESULT:
+    return atof(value);				// This is null terminated
+  }
+  return 0.0;					// Impossible
+}
+
+
+/* Get the value of a variable as an integer */
+
+longlong user_var_entry::val_int(my_bool *null_value)
+{
+  if ((*null_value= (value == 0)))
+    return LL(0);
+
+  switch (type) {
+  case REAL_RESULT:
+    return (longlong) *(double*) value;
+  case INT_RESULT:
+    return *(longlong*) value;
+  case STRING_RESULT:
+    return strtoull(value,NULL,10);		// String is null terminated
+  }
+  return LL(0);					// Impossible
 }
 
 
+/* Get the value of a variable as a string */
+
+String *user_var_entry::val_str(my_bool *null_value, String *str,
+				uint decimals)
+{
+  if ((*null_value= (value == 0)))
+    return (String*) 0;
+
+  switch (type) {
+  case REAL_RESULT:
+    str->set(*(double*) value, decimals, &my_charset_bin);
+    break;
+  case INT_RESULT:
+    str->set(*(longlong*) value, &my_charset_bin);
+    break;
+  case STRING_RESULT:
+    if (str->copy(value, length, collation.collation))
+      str= 0;					// EOM error
+  }
+  return(str);
+}
+
+
+/*
+  This functions is invoked on SET @variable or @variable:= expression.
+
+  SYNOPSIS
+    Item_func_set_user_var::update()
+
+  NOTES
+    We have to store the expression as such in the variable, independent of
+    the value method used by the user
+
+  RETURN
+    0	Ok
+    1	EOM Error
+
+*/
+
 bool
 Item_func_set_user_var::update()
 {
+  bool res;
+  DBUG_ENTER("Item_func_set_user_var::update");
+  LINT_INIT(res);
+
   switch (cached_result_type) {
   case REAL_RESULT:
-    (void) val();
+  {
+    double value=args[0]->val();
+    res= update_hash((void*) &value,sizeof(value), REAL_RESULT, 
+		     &my_charset_bin, DERIVATION_NONE);
     break;
+  }
   case INT_RESULT:
-    (void) val_int();
+  {
+    longlong value=args[0]->val_int();
+    res= update_hash((void*) &value, sizeof(longlong), INT_RESULT,
+		     &my_charset_bin, DERIVATION_NONE);
     break;
+  }
+  break;
   case STRING_RESULT:
   {
-    char buffer[MAX_FIELD_WIDTH];
-    String tmp(buffer,sizeof(buffer),&my_charset_bin);
-    (void) val_str(&tmp);
+    String *tmp;
+    tmp=args[0]->val_str(&value);
+    if (!tmp)					// Null value
+      res= update_hash((void*) 0, 0, STRING_RESULT, &my_charset_bin,
+		       DERIVATION_NONE);
+    else
+      res= update_hash((void*) tmp->ptr(), tmp->length(), STRING_RESULT,
+		       tmp->charset(), args[0]->collation.derivation);
     break;
   }
   case ROW_RESULT:
@@ -2202,44 +2304,32 @@ Item_func_set_user_var::update()
     DBUG_ASSERT(0);
     break;
   }
-  return current_thd->is_fatal_error;
+  DBUG_RETURN(res);
 }
 
 
-double
-Item_func_set_user_var::val()
+double Item_func_set_user_var::val()
 {
-  double value=args[0]->val();
-  update_hash((void*) &value,sizeof(value), REAL_RESULT, 
-    &my_charset_bin, DERIVATION_NONE);
-  return value;
+  update();					// Store expression
+  return entry->val(&null_value);
 }
 
-longlong
-Item_func_set_user_var::val_int()
+longlong Item_func_set_user_var::val_int()
 {
-  longlong value=args[0]->val_int();
-  update_hash((void*) &value, sizeof(longlong), INT_RESULT,
-	      &my_charset_bin, DERIVATION_NONE);
-  return value;
+  update();					// Store expression
+  return entry->val_int(&null_value);
 }
 
-String *
-Item_func_set_user_var::val_str(String *str)
+String *Item_func_set_user_var::val_str(String *str)
 {
-  String *res=args[0]->val_str(str);
-  if (!res)					// Null value
-    update_hash((void*) 0, 0, STRING_RESULT, &my_charset_bin, DERIVATION_NONE);
-  else
-    update_hash((void*) res->ptr(), res->length(), STRING_RESULT,
-		res->charset(), args[0]->collation.derivation);
-  return res;
+  update();					// Store expression
+  return entry->val_str(&null_value, str, decimals);
 }
 
 
 void Item_func_set_user_var::print(String *str)
 {
-  str->append('(');
+  str->append("(@@",3);
   str->append(name.str,name.length);
   str->append(":=",2);
   args[0]->print(str);
@@ -2247,89 +2337,29 @@ void Item_func_set_user_var::print(String *str)
 }
 
 
-user_var_entry *Item_func_get_user_var::get_entry()
-{
-  if (!var_entry  || ! var_entry->value)
-  {
-    null_value=1;
-    return 0;
-  }
-  null_value=0;
-  return var_entry;
-}
-
-
 String *
 Item_func_get_user_var::val_str(String *str)
 {
-  user_var_entry *entry=get_entry();
-  if (!entry)
-    return NULL;
-  switch (entry->type) {
-  case REAL_RESULT:
-    str->set(*(double*) entry->value,decimals, &my_charset_bin);
-    break;
-  case INT_RESULT:
-    str->set(*(longlong*) entry->value, &my_charset_bin);
-    break;
-  case STRING_RESULT:
-    if (str->copy(entry->value, entry->length, entry->collation.collation))
-    {
-      null_value=1;
-      return NULL;
-    }
-    break;
-  case ROW_RESULT:
-  default:
-    // This case should never be choosen
-    DBUG_ASSERT(0);
-    break;
-  }
-  return str;
+  DBUG_ENTER("Item_func_get_user_var::val_str");
+  if (!var_entry)
+    return (String*) 0;				// No such variable
+  DBUG_RETURN(var_entry->val_str(&null_value, str, decimals));
 }
 
 
 double Item_func_get_user_var::val()
 {
-  user_var_entry *entry=get_entry();
-  if (!entry)
-    return 0.0;
-  switch (entry->type) {
-  case REAL_RESULT:
-    return *(double*) entry->value;
-  case INT_RESULT:
-    return (double) *(longlong*) entry->value;
-  case STRING_RESULT:
-    return atof(entry->value);			// This is null terminated
-  case ROW_RESULT:
-  default:
-    // This case should never be choosen
-    DBUG_ASSERT(0);
-    return 0; 
-  }
-  return 0.0;					// Impossible
+  if (!var_entry)
+    return 0.0;					// No such variable
+  return (var_entry->val(&null_value));
 }
 
 
 longlong Item_func_get_user_var::val_int()
 {
-  user_var_entry *entry=get_entry();
-  if (!entry)
-    return LL(0);
-  switch (entry->type) {
-  case REAL_RESULT:
-    return (longlong) *(double*) entry->value;
-  case INT_RESULT:
-    return *(longlong*) entry->value;
-  case STRING_RESULT:
-    return strtoull(entry->value,NULL,10);	// String is null terminated
-  case ROW_RESULT:
-  default:
-    // This case should never be choosen
-    DBUG_ASSERT(0);
-    return 0;
-  }
-  return LL(0);					// Impossible
+  if (!var_entry)
+    return LL(0);				// No such variable
+  return (var_entry->val_int(&null_value));
 }
 
 
@@ -2348,7 +2378,8 @@ void Item_func_get_user_var::fix_length_and_dec()
   decimals=NOT_FIXED_DEC;
   max_length=MAX_BLOB_WIDTH;
 
-  var_entry= get_variable(&thd->user_vars, name, 0);
+  if (!(var_entry= get_variable(&thd->user_vars, name, 0)))
+    null_value= 1;
 
   if (!(opt_bin_log && is_update_query(thd->lex.sql_command)))
     return;