Re: [bug]Malformed -*- line

[CHENG Gao]

I have a silly question.

,----[ C-h f set-text-properties RET ]
| set-text-properties is a built-in function in `src/textprop.c'.
| (set-text-properties start end properties &optional object)
| 
| Completely replace properties of text from start to end.
| The third argument properties is the new property list.
| If the optional fourth argument object is a buffer (or nil, which means
| the current buffer), start and end are buffer positions (integers or
| markers).  If object is a string, start and end are 0-based indices into it.
| If properties is nil, the effect is to remove all properties from
| the designated part of object.
`----

How does the fourth argument, object, if omitted in function call, get
its value? Just as in
,----
| (set-text-properties (point-min) (point-max) nil)
`----

Sorry I dont know too much about C. I just checked set_text_properties
(start, end, properties, object, signal_after_change_p),
I saw 
,----
| if (NILP (object))
|     XSETBUFFER (object, current_buffer);
`----
so I guess in gnus-registry.el call of set-text-properties should be
changed to 

,----
| (set-text-properties (point-min) (point-max) nil nil)
`----

otherwise I dont understand how 'object' gets it value.