On Tue, Oct 21, 2014 at 05:29:53PM -0400, Tyler Hicks wrote:
> > 101 if (data[0] < 192) {
> > 102 /* One-byte length */
> > 103 (*size) = (unsigned char)data[0];
> > 104 (*length_size) = 1;
> > 105 } else if (data[0] < 224) {
> > 106 /* Two-byte length */
> > 107 (*size) = (((unsigned char)(data[0]) - 192) * 256);
> > ^^^^^^^^^^^^^^^
> > 108 (*size) += ((unsigned char)(data[1]) + 192);
> > ^^^^^^^^^^^^^^^
> > These casts are no-ops because they are "data" is an unsigned char
> > pointer already. Then the value is type promoted to int, we subtract
> > 192 giving a negative number and we multiply by 256 giving a slightly
> > larger negative then we save it as a very large positive.
>
> Subtracting 192 from data[0] should never result in a negative number.
> We know that data[0] is greater than or equal to 192 (and less than 224)
> because the previous conditional was false.
>
Oh right. Duh... Thanks.
We could remove the casting though because it's a no-op?
regards,
dan carpenter
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