Re: [avr-libc-dev] [bugs #10420] sscanf(), If there is a decimal number followed by the character '_' in the buffer, you can't get the the number.

[Joerg Wunsch]

As Theodore A. Roth wrote:

>     378                     if (j > 9)
>     379                         j -= 'a' - '0' - 10;
>     380                     if (j < 0 || j >= base) {

I think I see the logical flaw in this now, too.  I tried to minimize
the code required for this check, but obviously opened a window for
false positives by that.

> I have attached a patch that seems to fix the problem for me. Tested on
> a mega128, using both "<1/dr_2_600" and "<1/dr_2\\600" for buf and the
> respective fmt strings.

Patch looks OK to me except of some whitespace inconsistencies.  You've
been using spaces here, and tabs there to indent the code.

> One other thing. line 379 is hideous. The distribution of the
> subtraction via the '-=' operator makes this code very difficult to read
> and understand what it is doing exactly. This is a case where parens
> should be used:
> 
>   j -= ('a' + '0' + 10);
> 
> is so much more explicit and makes the code easier to understand.

Yeah, blame me on this one. ;-)

-- 
J"org Wunsch                                           Unix support engineer
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