Fixes during review of new code

- Mostly indentation fixes
- Added missing test
- Ensure that Item_func_case() checks for stack overruns
- Use real_item() instead of (Item_ref*) item
- Fixed wrong error handling

sql/item_cmpfunc.cc

@@ -275,7 +275,7 @@ int Arg_comparator::set_compare_func(Item_bool_func2 *item, Item_result type)
   owner= item;
   func= comparator_matrix[type]
                          [test(owner->functype() == Item_func::EQUAL_FUNC)];
-  switch(type) {
+  switch (type) {
   case ROW_RESULT:
   {
     uint n= (*a)->cols();
@@ -1581,6 +1581,21 @@ my_decimal *Item_func_case::val_decimal(my_decimal *decimal_value)
 }
 
 
+bool Item_func_case::fix_fields(THD *thd, struct st_table_list *tables,
+                                Item **ref)
+{
+  /*
+    buff should match stack usage from
+    Item_func_case::val_int() -> Item_func_case::find_item()
+  */
+  char buff[MAX_FIELD_WIDTH*2+sizeof(String)*2+sizeof(String*)*2+sizeof(double)*2+sizeof(longlong)*2];
+  if (check_stack_overrun(thd, STACK_MIN_SIZE, buff))
+    return TRUE;				// Fatal error flag is set!
+  return Item_func::fix_fields(thd, tables, ref);
+}
+
+
+
 void Item_func_case::fix_length_and_dec()
 {
   Item **agg;