Re: problem report #101

[Kenichi Handa <handa@m17n.org>]

In article <200812011659.mB1GxPZD015344@mothra.ics.uci.edu>, Dan Nicolaescu <dann@ics.uci.edu> writes:

> CID: 101
> Checker: FORWARD_NULL (help)
> File: base/src/emacs/src/font.c
> Function: font_at
> Description: Variable "face" tracked as NULL was passed to a function that dereferences it.

[...]
> Event var_deref_op: Variable "face" tracked as NULL was dereferenced.
> Event var_deref_model: Variable "face" tracked as NULL was passed to a function that dereferences it. [model]
> Also see events: [var_compare_op][var_deref_model]
> At conditional (5): "c < 128" taking true path

> 3646 	      int face_id = FACE_FOR_CHAR (f, face, c, pos, string);
> 3647 	      face = FACE_FROM_ID (f, face_id);
> 3648 	    }

Here, "face" is a return value of
face_at_string/buffer_position, and thus is never NULL.
Which do you think is better; ignore this waring or use a
new macro FACE_FROM_ID_NO_CHECK instead of FACE_FROM_ID?

/* Like FACE_FROM_ID but don't check the validity of ID.  */

#define FACE_FROM_ID_NO_CHECK(F, ID)	\
  (FRAME_FACE_CACHE (F)->faces_by_id[ID])

---
Kenichi Handa
handa@ni.aist.go.jp