bk commit into 5.0 tree (evgen:1.2320) BUG#16861

[eugene]

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5.0 repository of evgen. When evgen does a push these changes will
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ChangeSet@stripped, 2006-12-06 21:37:16+03:00, evgen@stripped +4 -0
  Fixed bug#16861: User defined variable can have a wrong value if a tmp table was
  used.
  
  The Item::save_in_field() function is called from fill_record() to fill fields 
  with data for a new row in a CREATE TABLE ... SELECT statement.
  It calls val_xxx() methods in order to get values. Due to this
  Item_func_set_user_var object returns values from the original table, not from
  a temporary one.
  
  The save_in_field() member function is added to the Item_func_set_user_var
  class. It detects when the result field should be used and uses it in such
  cases.

  mysql-test/r/user_var.result@stripped, 2006-12-06 21:04:16+03:00, evgen@stripped +8 -1
    Extended the test case for bug#18681: User defined variable can have a wrong value if
a tmp table was used.

  mysql-test/t/user_var.test@stripped, 2006-12-06 21:03:34+03:00, evgen@stripped +4 -1
    Extended the test case for bug#18681: User defined variable can have a wrong value if
a tmp table was
    used.

  sql/item_func.cc@stripped, 2006-12-06 21:09:13+03:00, evgen@stripped +64 -0
    Bug#16861: User defined variable can have a wrong value if a tmp table was used.
    Added the save_in_field() member function to the Item_func_set_user_var class.

  sql/item_func.h@stripped, 2006-12-06 21:06:45+03:00, evgen@stripped +1 -0
    Bug#16861: User defined variable can have a wrong value if a tmp table was used.
    Added the save_in_field() member function to the Item_func_set_user_var class.

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	evgen
# Host:	moonbone.local
# Root:	/work/16861-bug-5.0-opt-mysql

--- 1.315/sql/item_func.cc	2006-12-04 15:25:41 +03:00
+++ 1.316/sql/item_func.cc	2006-12-06 21:09:13 +03:00
@@ -4040,6 +4040,70 @@
     Item::make_field(tmp_field);
 }
 
+int Item_func_set_user_var::save_in_field(Field *field, bool no_conversions)
+{
+  bool use_result_field= (result_field && result_field != field);
+  int error;
+
+  if (use_result_field)
+  {
+    check(1);
+    update();
+  }
+  if (result_type() == STRING_RESULT ||
+      result_type() == REAL_RESULT &&
+      field->result_type() == STRING_RESULT)
+  {
+    String *result;
+    CHARSET_INFO *cs= collation.collation;
+    char buff[MAX_FIELD_WIDTH];		// Alloc buffer for small columns
+    str_value.set_quick(buff, sizeof(buff), cs);
+    result= use_result_field ?
+              entry->val_str(&null_value, &str_value, decimals) :
+              val_str(&str_value);
+    if (null_value)
+    {
+      str_value.set_quick(0, 0, cs);
+      return set_field_to_null_with_conversions(field, no_conversions);
+    }
+
+    /* NOTE: If null_value == FALSE, "result" must be not NULL.  */
+
+    field->set_notnull();
+    error=field->store(result->ptr(),result->length(),cs);
+    str_value.set_quick(0, 0, cs);
+  }
+  else if (result_type() == REAL_RESULT)
+  {
+    double nr= use_result_field ? entry->val_real(&null_value) : val_real();
+    if (null_value)
+      return set_field_to_null(field);
+    field->set_notnull();
+    error=field->store(nr);
+  }
+  else if (result_type() == DECIMAL_RESULT)
+  {
+    my_decimal decimal_value;
+    my_decimal *value=
+      use_result_field ? entry->val_decimal(&null_value, &decimal_value) :
+                                            val_decimal(&decimal_value);
+    if (null_value)
+      return set_field_to_null(field);
+    field->set_notnull();
+    error=field->store_decimal(value);
+  }
+  else
+  {
+    longlong nr= use_result_field ? entry->val_int(&null_value) : val_int();
+    if (null_value)
+      return set_field_to_null_with_conversions(field, no_conversions);
+    field->set_notnull();
+    error=field->store(nr, unsigned_flag);
+  }
+  return error;
+}
+
+
 String *
 Item_func_get_user_var::val_str(String *str)
 {

--- 1.160/sql/item_func.h	2006-11-28 16:47:47 +03:00
+++ 1.161/sql/item_func.h	2006-12-06 21:06:45 +03:00
@@ -1189,6 +1189,7 @@
   void print(String *str);
   void print_as_stmt(String *str);
   const char *func_name() const { return "set_user_var"; }
+  int save_in_field(Field *field, bool no_conversions);
 };
 
 

--- 1.43/mysql-test/r/user_var.result	2006-10-04 18:49:37 +04:00
+++ 1.44/mysql-test/r/user_var.result	2006-12-06 21:04:16 +03:00
@@ -301,7 +301,14 @@
 select @var;
 @var
 3
-drop table t1;
+create table t2 as select @var:=f2 from t1 group by f1 order by f2 desc limit 1;
+select * from t2;
+@var:=f2
+3
+select @var;
+@var
+3
+drop table t1,t2;
 insert into city 'blah';
 ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to
your MySQL server version for the right syntax to use near ''blah'' at line 1
 SHOW COUNT(*) WARNINGS;

--- 1.38/mysql-test/t/user_var.test	2006-10-04 18:49:37 +04:00
+++ 1.39/mysql-test/t/user_var.test	2006-12-06 21:03:34 +03:00
@@ -210,7 +210,10 @@
 insert into t1 values (1,2),(2,3),(3,1);
 select @var:=f2 from t1 group by f1 order by f2 desc limit 1;
 select @var;
-drop table t1;
+create table t2 as select @var:=f2 from t1 group by f1 order by f2 desc limit 1;
+select * from t2;
+select @var;
+drop table t1,t2;
 
 #
 # Bug#19024 - SHOW COUNT(*) WARNINGS not return Errors