Fix for bug #8431 (FLOOR returns incorrect result)

mysql-test/r/type_newdecimal.result:
  test result fixed
mysql-test/t/type_newdecimal.test:
  test case enlarged for FLOOR and CEILING functions
sql/item_func.cc:
  floor::int_op fixed - it should work differently depending on operand's type

mysql-test/r/type_newdecimal.result

@@ -733,6 +733,9 @@ abs(9999999999999999999999)
 select abs(-9999999999999999999999);
 abs(-9999999999999999999999)
 9999999999999999999999
+select ceiling(999999999999999999);
+ceiling(999999999999999999)
+999999999999999999
 select ceiling(99999999999999999999);
 ceiling(99999999999999999999)
 99999999999999999999
@@ -741,13 +744,16 @@ ceiling(9.9999999999999999999)
 10
 select ceiling(-9.9999999999999999999);
 ceiling(-9.9999999999999999999)
--10
+-9
+select floor(999999999999999999);
+floor(999999999999999999)
+999999999999999999
 select floor(9999999999999999999999);
 floor(9999999999999999999999)
 9999999999999999999999
 select floor(9.999999999999999999999);
 floor(9.999999999999999999999)
-10
+9
 select floor(-9.999999999999999999999);
 floor(-9.999999999999999999999)
 -10

mysql-test/t/type_newdecimal.test

@@ -601,6 +601,7 @@ select abs(9999999999999999999999);
 select abs(-9999999999999999999999);
 #-- should return 9999999999999999999999
 #
+select ceiling(999999999999999999);
 select ceiling(99999999999999999999);
 #-- should return 99999999999999999999
 #
@@ -610,6 +611,7 @@ select ceiling(9.9999999999999999999);
 select ceiling(-9.9999999999999999999);
 #-- should return 9
 #
+select floor(999999999999999999);
 select floor(9999999999999999999999);
 #-- should return 9999999999999999999999
 #

sql/item_func.cc

@@ -1638,14 +1638,14 @@ longlong Item_func_ceiling::int_op()
   case DECIMAL_RESULT:
   {
     my_decimal dec_buf, *dec;
-    if ((dec= decimal_op(&dec_buf)))
+    if ((dec= Item_func_ceiling::decimal_op(&dec_buf)))
       my_decimal2int(E_DEC_FATAL_ERROR, dec, unsigned_flag, &result);
     else
       result= 0;
     break;
   }
   default:
-    result= (longlong)real_op();
+    result= (longlong)Item_func_ceiling::real_op();
   };
   return result;
 }
@@ -1676,13 +1676,25 @@ my_decimal *Item_func_ceiling::decimal_op(my_decimal *decimal_value)
 
 longlong Item_func_floor::int_op()
 {
-  /*
-    the volatile's for BUG #3051 to calm optimizer down (because of gcc's
-    bug)
-  */
-  volatile double value= args[0]->val_real();
-  null_value= args[0]->null_value;
-  return (longlong) floor(value);
+  longlong result;
+  switch (args[0]->result_type()) {
+  case INT_RESULT:
+    result= args[0]->val_int();
+    null_value= args[0]->null_value;
+    break;
+  case DECIMAL_RESULT:
+  {
+    my_decimal dec_buf, *dec;
+    if ((dec= Item_func_floor::decimal_op(&dec_buf)))
+      my_decimal2int(E_DEC_FATAL_ERROR, dec, unsigned_flag, &result);
+    else
+      result= 0;
+    break;
+  }
+  default:
+    result= (longlong)Item_func_floor::real_op();
+  };
+  return result;
 }