Subject: Re: tgetstr bug
To: None <tech-userlevel@netbsd.org>
From: Christos Zoulas <christos@astron.com>
List: tech-userlevel
Date: 12/18/2006 06:07:37
In article <em32vf$mi4$1@sea.gmane.org>,
Valeriy E. Ushakov <uwe@ptc.spbu.ru> wrote:
>Christos Zoulas <christos@astron.com> wrote:
>
>> In article <200612141505.51129.bruno@clisp.org>,
>> Bruno Haible <bruno@clisp.org> wrote:
>>>tgetstr ("md", NULL) crashes on NetBSD. It's here:
>>>
>>>src/lib/libterm/termcap.c:
>>>
>>>char *
>>>t_getstr(struct tinfo *info, const char *id, char **area, size_t *limit)
>>>{
>>>...
>>> _DIAGASSERT(limit != NULL);
>>> *limit = i; <=====
>>> free(s);
>>> return NULL;
>>>...
>>>}
>>>
>>>Other systems support tgetstr ("md", NULL) without problems, and
>>>return the string in a statically allocated buffer.
>>
>> The code that passes NULL is non-portable. According to the TOG:
>>
>> The tgetstr() function gets the string entry for id. If area is
>> not a null pointer and does not point to a null pointer, tgetstr()
>> copies the string entry into the buffer pointed to by *area and
>> advances the variable pointed to by area to the first byte after
>> the copy of the string entry.
>>
>> By making tgetstr(id, NULL) work, we are encouraging non-portable
>> behavior.
>
>Hmm, why is that non-portable? I read TOG text as that tgetstr
>returns the capability *and*, if area is not null, also copies the
>capability string into the area.
>
>Do I miss something?
No, you read it differently than I did. Anyway, it is simple enough
to fix, and I can see that this interpretation of the text is valid.
christos