Re: Problem report #13 FALSE

[Andreas Schwab <schwab@suse.de>]

Kenichi Handa <handa@m17n.org> writes:

> Dan Nicolaescu <dann@ics.uci.edu> writes:
>
>> CID: 13
>> Checker: FORWARD_NULL (help)
>> File: emacs/src/coding.c
>> Function: encode_coding_string
>> Description: Variable "(coding)->cmp_data" tracked as NULL was passed to a function that dereferences it.
>
> I see no bug here.   A member of (coding)->cmp_data is
> accessed only after checking (coding)->cmp_data is not NULL.
>
>> Event var_compare_op: Added "(coding)->cmp_data" due to comparison "(coding)->cmp_data == 0"
>> Also see events: [var_deref_model]
>> At conditional (1): "(coding)->cmp_data == 0" taking true path
>
>> 6435 	  if (coding->type != coding_type_ccl
>> 6436 	      && (! coding->cmp_data || coding->cmp_data->used == 0))
>> 6437 	    {
>
> Does the checker require it to be writen as below?
>
>> 6436 	      && (coding->cmp_data ? coding->cmp_data->used == 0 : 1))

That would be stupid, since it would be a major obfucation.  But that's
not the point of the report, the derefence is supposed to happen in
encode_coding.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
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