Wireshark-dev: Re: [Wireshark-dev] [Wireshark-commits] rev 47188: /trunk/ui/gtk/ /trunk/ui/gtk/

From: Jaap Keuter <jaap.keuter@xxxxxxxxx>
Date: Mon, 21 Jan 2013 08:04:50 +0100
Hi,

I think I have been staring at line 2895 too long. Since I didn't have  Coverity
at my disposal this weekend I tried to take a stab at it, but couldn't verify
it. It looks like a strange construction anyway.
prefs_p = read_configuration_files (&gdp_path, &dp_path); is what makes it work,
but Coverity doesn't pick up on that. We may as well rewrite this bit.

Thanks,
Jaap

On 01/20/2013 11:14 PM, Guy Harris wrote:
> 
> On Jan 20, 2013, at 1:45 PM, jake@xxxxxxxxxxxxx wrote:
> 
>> http://anonsvn.wireshark.org/viewvc/viewvc.cgi?view=rev&revision=47188
>>
>> User: jake
>> Date: 2013/01/20 01:45 PM
>>
>> Log:
>> Fix for CID 715142.
>> Be aware that the short-circuit evaluation only applies to the 
>> first operand of a logical AND expression.
> 
> ...but if the second operand is itself a logical AND expression, short-circuit evaluation applies to the first operand of *that* expression.  I'm not sure what that change actually changes; would not both evaluate as
> 
> 	if global_capture_opts.num_selected == 0
> 	then
> 		if prefs.capture_device != NULL
> 		then
> 			if *prefs_p->capture_device != '\0'
> 			then
> 				TRUE
> 			else
> 				FALSE
> 		else
> 			FALSE
> 	else
> 		FALSE
> 
> (expression syntax is C syntax, if/then syntax isn't)?
> 
> At least when I look at 715142, I think the problem about which it's complaining is that, unless prefs_p == &prefs, establishing that prefs.capture_devices != NULL does nothing to establish that prefs_p->capture_devices is != NULL, and therefore does nothing to establish that *prefs_p->capture_device is a valid reference.