Less commas

[Peter Alexander]

On 2/01/11 8:04 PM, Walter Bright wrote:
> bearophile wrote:
>> A common bug in Linux kernel:
>>
>> if(!state->card->
>> ac97_status&CENTER_LFE_ON)
>> val&=~DSP_BIND_CENTER_LFE;
>>
>> The fix is to replace (!E & C) with (!(E & C)).
>>
>> Currently D acts like C:
>>
>> void main() {
>> uint x, y;
>> if (!x & y) {}
>> }
>>
>> - 96 instances of this bug in Linux from 2.6.13 (August 2005) to
>> v2.6.28 (December 2008).
>> - 58 instances of this bug in 2.6.20 (February 2007)
>> - 2 in Linux-next (October 10, 2009)
>>
>> They have faced and reduced the number of such bugs using Coccinelle,
>> see pages 8-9 here:
>> http://coccinelle.lip6.fr/papers/fosdem10.pdf
>
> This is great stuff, bearophile. Thanks for finding that. Please add
> this as an enhancement request to bugzilla (disallowing (!x&y)
> expressions).

That really surprises me that it's a common bug. Isn't it obvious that ! 
has higher precedence than &? Or have I totally misunderstood the cause 
of the bug?