Item_func_equal made uniform

mysql-test/r/row_test.result:
  Equal test
mysql-test/t/row_test.test:
  Equal test

mysql-test/r/row_test.result

@@ -22,6 +22,12 @@ SELECT (1,2,3)>=(1+1,2,3);
 SELECT (1,2,3)<>(1+1,2,3);
 (1,2,3)<>(1+1,2,3)
 1
+SELECT (NULL,2,3)=(NULL,2,3);
+(NULL,2,3)=(NULL,2,3)
+NULL
+SELECT (NULL,2,3)<=>(NULL,2,3);
+(NULL,2,3)<=>(NULL,2,3)
+1
 SELECT (1,2,(3,4,5))=(1,2,(3,4,5));
 (1,2,(3,4,5))=(1,2,(3,4,5))
 1

mysql-test/t/row_test.test

@@ -6,6 +6,8 @@ SELECT (1,2,3)>(1+1,2,3);
 SELECT (1,2,3)<=(1+1,2,3);
 SELECT (1,2,3)>=(1+1,2,3);
 SELECT (1,2,3)<>(1+1,2,3);
+SELECT (NULL,2,3)=(NULL,2,3);
+SELECT (NULL,2,3)<=>(NULL,2,3);
 SELECT (1,2,(3,4,5))=(1,2,(3,4,5));
 SELECT ('test',2,3.33)=('test',2,3.33);
 -- error 1239

sql/item_cmpfunc.cc

@@ -88,7 +88,6 @@ static bool convert_constant_item(Field *field, Item **item)
   return 0;
 }
 
-
 void Item_bool_func2::fix_length_and_dec()
 {
   max_length=1;					// Function returns 0 or 1
@@ -130,20 +129,9 @@ void Item_bool_func2::fix_length_and_dec()
 int Arg_comparator::set_compare_func(Item_bool_func2 *item, Item_result type)
 {
   owner= item;
-  switch (type)
-  {
-  case STRING_RESULT:
-    func= &Arg_comparator::compare_string;
-    break;
-  case REAL_RESULT:
-    func= &Arg_comparator::compare_real;
-    break;
-  case INT_RESULT:
-    func= &Arg_comparator::compare_int;
-    break;
-  case ROW_RESULT:
-  {
-    func= &Arg_comparator::compare_row;
+  func= comparator_matrix[type][owner->equal];
+  if (type == ROW_RESULT)
+  {
     uint n= args[0]->cols();
     if (n != args[1]->cols())
     {
@@ -164,8 +152,6 @@ int Arg_comparator::set_compare_func(Item_bool_func2 *item, Item_result type)
       current_thd->fatal_error= 1;
       return 1;
     }
-    break;
-  }
   }
   return 0;
 }
@@ -185,6 +171,18 @@ int Arg_comparator::compare_string()
   return -1;
 }
 
+int Arg_comparator::compare_e_string()
+{
+  String *res1,*res2;
+  res1= args[0]->val_str(&owner->tmp_value1);
+  res2= args[1]->val_str(&owner->tmp_value2);
+  if (!res1 || !res2)
+    return test(res1 == res2);
+  return (owner->binary() ? test(stringcmp(res1, res2) == 0) :
+	    test(sortcmp(res1, res2) == 0));
+}
+
+
 int Arg_comparator::compare_real()
 {
   double val1= args[0]->val();
@@ -203,6 +201,14 @@ int Arg_comparator::compare_real()
   return -1;
 }
 
+int Arg_comparator::compare_e_real()
+{
+  double val1= args[0]->val();
+  double val2= args[1]->val();
+  if (args[0]->null_value || args[1]->null_value)
+    return test(args[0]->null_value && args[1]->null_value);
+  return test(val1 == val2);
+}
 
 int Arg_comparator::compare_int()
 {
@@ -222,6 +228,16 @@ int Arg_comparator::compare_int()
   return -1;
 }
 
+int Arg_comparator::compare_e_int()
+{
+  longlong val1= args[0]->val_int();
+  longlong val2= args[1]->val_int();
+  if (args[0]->null_value || args[1]->null_value)
+    return test(args[0]->null_value && args[1]->null_value);
+  return test(val1 == val2);
+}
+
+
 int Arg_comparator::compare_row()
 {
   int res= 0;
@@ -236,6 +252,19 @@ int Arg_comparator::compare_row()
   return res;
 }
 
+int Arg_comparator::compare_e_row()
+{
+  int res= 0;
+  uint n= args[0]->cols();
+  for (uint i= 0; i<n; i++)
+  {
+    if ((res= comparators[i].compare()))
+      return 1;
+  }
+  return 1;
+}
+
+
 longlong Item_func_eq::val_int()
 {
   int value= arg_store.compare();
@@ -247,49 +276,15 @@ longlong Item_func_eq::val_int()
 void Item_func_equal::fix_length_and_dec()
 {
   Item_bool_func2::fix_length_and_dec();
-  cmp_result_type=item_cmp_type(args[0]->result_type(),args[1]->result_type());
   maybe_null=null_value=0;
+  set_cmp_func();
 }
 
 longlong Item_func_equal::val_int()
 {
-  switch (cmp_result_type) {
-  case STRING_RESULT:
-  {
-    String *res1,*res2;
-    res1=args[0]->val_str(&tmp_value1);
-    res2=args[1]->val_str(&tmp_value2);
-    if (!res1 || !res2)
-      return test(res1 == res2);
-    return (binary() ? test(stringcmp(res1,res2) == 0) :
-	    test(sortcmp(res1,res2) == 0));
-  }
-  case REAL_RESULT:
-  {
-    double val1=args[0]->val();
-    double val2=args[1]->val();
-    if (args[0]->null_value || args[1]->null_value)
-      return test(args[0]->null_value && args[1]->null_value);
-    return test(val1 == val2);
-  }
-  case INT_RESULT:
-  {
-    longlong val1=args[0]->val_int();
-    longlong val2=args[1]->val_int();
-    if (args[0]->null_value || args[1]->null_value)
-      return test(args[0]->null_value && args[1]->null_value);
-    return test(val1 == val2);
-  }
-  case ROW_RESULT:
-  {
-    my_error(ER_WRONG_USAGE, MYF(0), "row", "<=>");
-    return 0;
-  }
-  }
-  return 0;					// Impossible
+  return arg_store.compare();
 }
 
-
 longlong Item_func_ne::val_int()
 {
   int value= arg_store.compare();

sql/item_cmpfunc.h

@@ -34,8 +34,9 @@ class Item_bool_func2 :public Item_int_func
 {						/* Bool with 2 string args */
 protected:
   String tmp_value1,tmp_value2;
+  bool equal;
 public:
-  Item_bool_func2(Item *a,Item *b) :Item_int_func(a,b) {}
+  Item_bool_func2(Item *a,Item *b) :Item_int_func(a,b), equal(0) {}
   void fix_length_and_dec();
   void set_cmp_func()
   {
@@ -85,11 +86,10 @@ class Item_func_eq :public Item_bool_rowready_func2
   const char *func_name() const { return "="; }
 };
 
-class Item_func_equal :public Item_bool_func2
+class Item_func_equal :public Item_bool_rowready_func2
 {
-  Item_result cmp_result_type;
 public:
-  Item_func_equal(Item *a,Item *b) :Item_bool_func2(a,b) { };
+  Item_func_equal(Item *a,Item *b) :Item_bool_rowready_func2(a,b) { equal=1; };
   longlong val_int();
   void fix_length_and_dec();
   enum Functype functype() const { return EQUAL_FUNC; }

sql/item_func.h

@@ -55,6 +55,12 @@ class Arg_comparator: public Sql_alloc
   int compare_real();            // compare args[0] & args[1]
   int compare_int();             // compare args[0] & args[1]
   int compare_row();             // compare args[0] & args[1]
+  int compare_e_string();	 // compare args[0] & args[1]
+  int compare_e_real();          // compare args[0] & args[1]
+  int compare_e_int();           // compare args[0] & args[1]
+  int compare_e_row();           // compare args[0] & args[1]
+
+  static arg_cmp_func comparator_matrix [4][2];
 
   friend class Item_func;
 };

sql/mysqld.cc

@@ -337,7 +337,11 @@ ulong query_cache_size=0;
 ulong query_cache_limit=0;
 Query_cache query_cache;
 #endif
-
+arg_cmp_func Arg_comparator::comparator_matrix[4][2] = 
+{{&Arg_comparator::compare_string, &Arg_comparator::compare_e_string},
+ {&Arg_comparator::compare_real, &Arg_comparator::compare_e_real},
+ {&Arg_comparator::compare_int, &Arg_comparator::compare_e_int},
+ {&Arg_comparator::compare_row, &Arg_comparator::compare_e_row}};
 #ifdef HAVE_SMEM
 static char *shared_memory_base_name=default_shared_memory_base_name;
 static bool opt_enable_shared_memory = 0;