Cleanups during review of code

Fixed newly introduced bug in rollup


client/mysqldump.c:
  Safer buffer allocation
  Removed wrong assert
mysql-test/r/olap.result:
  more tests
mysql-test/t/olap.test:
  more tests
sql/handler.cc:
  Simple cleanup
  Fixed wrong check for next digit (wrong debug output)
sql/item.cc:
  Replace shrink_to_length() with mark_as_const() as the former allowed one to do changes to the string
sql/item_sum.cc:
  Change reference to pointer
  Trivial optimzation of testing 'allways_null'
sql/mysqld.cc:
  Proper indentation of comment
sql/sql_select.cc:
  Fixed newly introduced bug in rollup
sql/sql_string.h:
  Remove not needed 'shrink_to_length()'
  Added 'mark_as_const()' to be used when one want to ensure that a string is not changed

1 files changed, 9 insertions, 7 deletions

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 1e05400e88e..f8caabaead4 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -10145,20 +10145,18 @@ end_write_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
                        join->sum_funcs_end[send_group_parts]);
 	if (join->having && join->having->val_int() == 0)
           error= -1;
-        else if ((error=table->file->write_row(table->record[0])))
+        else if ((error= table->file->write_row(table->record[0])))
 	{
 	  if (create_myisam_from_heap(join->thd, table,
 				      &join->tmp_table_param,
 				      error, 0))
 	    DBUG_RETURN(-1);		       
         }
-        if (join->rollup.state != ROLLUP::STATE_NONE && error <= 0)
+        if (join->rollup.state != ROLLUP::STATE_NONE)
 	{
 	  if (join->rollup_write_data((uint) (idx+1), table))
-	    error= 1;
+	    DBUG_RETURN(-1);
 	}
-	if (error > 0)
-	  DBUG_RETURN(-1);	  
 	if (end_of_records)
 	  DBUG_RETURN(0);
       }
@@ -12685,17 +12683,21 @@ bool JOIN::rollup_make_fields(List<Item> &fields_arg, List<Item> &sel_fields,
       {
 	/* Check if this is something that is part of this group by */
 	ORDER *group_tmp;
-	for (group_tmp= start_group, i-- ;
+	for (group_tmp= start_group, i= pos ;
              group_tmp ; group_tmp= group_tmp->next, i++)
 	{
 	  if (*group_tmp->item == item)
 	  {
+            Item_null_result *null_item;
 	    /*
 	      This is an element that is used by the GROUP BY and should be
 	      set to NULL in this level
 	    */
 	    item->maybe_null= 1;		// Value will be null sometimes
-            Item_null_result *null_item= rollup.null_items[i];
+            null_item= rollup.null_items[i];
+            DBUG_ASSERT(null_item->result_field == 0 ||
+                        null_item->result_field ==
+                        ((Item_field *) item)->result_field);
             null_item->result_field= ((Item_field *) item)->result_field;
             item= null_item;
 	    break;