prevent bufer underflow

walter harms wharms at bfs.de
Tue Jun 24 07:37:17 UTC 2008



Bernd Petrovitsch wrote:
> On Mon, 2008-06-23 at 17:49 +0200, walter harms wrote:
>> hi list,
>> this patch adds a check that
>              ^^^
>> the address p is larger the current buffer adress text when accessing p-1
>> because at begining p==text is possible.
>> the first place have a dot>text (cursor pos) it could be that p=q is assumed
>> no idea if this is true
>>
>> re,
>>  wh
>>
>>
>> --- editors/vi_org.c    2008-06-23 17:42:13.000000000 +0200
>> +++ ../vi.c     2008-06-23 17:38:10.000000000 +0200
>> @@ -1659,12 +1659,12 @@
>>                 cmdcnt = 0;
>>                 end_cmd_q();    // stop adding to q
>>                 last_status_cksum = 0;  // force status update
>> -               if ((p > text) && (p[-1] != '\n') && (dot > text)) {
>> +               if ((p[-1] != '\n') && (dot > text)) {
> 
> That looks like either your comment above is or the diff command was
> wrong (read: the from-file and to-file interchanged).
> 
> 	Bernd

obviously you are right. fortunately patch has -R (--reverse) option :)

re,
 wh



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