Re: [PATCH] diff: avoid stack-buffer-read-overrun for very long name

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


Junio C Hamano wrote:
> Jim Meyering <jim@xxxxxxxxxxxx> writes:
>
>> What do you think about replacing those two append-if-needed two-liners:
>>
>>     if (buffer2.len && buffer2.buf[buffer2.len - 1] != '/')
>>             strbuf_addch(&buffer2, '/');
>>
>> by something that readably encapsulates the idiom:
>>
>>     strbuf_append_if_absent (&buffer2, '/');
>>
>> (though the name isn't particularly apt, because you might
>> take "absent" to mean "not anywhere in the string," so maybe
>>   strbuf_append_if_not_already_at_end (ugly) or
>>   strbuf_append_uniq
>> )
>
> I am not good at names, but strbuf_terminate_with(&buffer2, '/')
> perhaps?

Maybe, but it still doesn't evoke the conditional nature
of don't-append-if-already-there the operation.  i.e., one
might wonder how it's different from "strbuf_append".

How about one of these?

  strbuf_ensure_suffix  // but might make you think suffix==more than 1 byte
  strbuf_ensure_last_byte    // maybe?
  strbuf_ensure_last_byte_is // rather long, but apt

>> There are several other uses that would benefit from such a transformation:
>> To find the easy ones, I ran this:
>>
>>   git grep -B1 "strbuf_addch.*'"|grep -A1 '!='
>>
>> I've manually marked/separated the ones that don't apply.
>>
>> Note how only 2 of the 6 candidates ensure that length is positive
>> before using ".len - 1":
>
> Yikes, that is embarrasing ;-)

Knowing you/git, each is because the buffer is known to be non-empty.
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Newbies FAQ]     [Linux Kernel Development]     [Free Online Dating]     [Gcc Help]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [V4L]     [Bugtraq]     [Free Online Dating]     [Photo]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]     [Fedora Users]     [Linux Resources]

Add to Google