Behaviour and processing of conditionals

Okay, so here's the deal, in most languages, and previously in LSL, when you have a conditional statement such as, if (A && B) then ... It's my understanding that first the A is processed, and if found TRUE, then B is processed. But should A be FALSE, then B is simply forgotten and skipped over.

Now I know that this is how LSL used to treat this kind of code, because I've been using a form of PointInPoly that requires this behaviour and it worked fine until recently. Now you wouldn't believe how badly I've been racking my brain trying to figure out why the script was now giving me a math error.

Apparently LSL now processes both conditions even if the first is false. Easily fixed now I know, simply nest another if statement. But still, why has this behaviour changed? Surely I'm not the only one that's noticed this?

I would never rely on a thing like that.
It is not documented anywhere and the code itself tells nothing about how the statement is interpreted.

I do not know about the order of processing but it still only works if both are TRUE

integer A = 1;
integer B = 1;

default {
	touch_start(integer n) {
		if(A&&B){
			llOwnerSay("both are true");
		}
	}
}

What is not working and do you have a code fragment to demo it?

This is the way LSL behaves, certainly -- processing B whether or not A is true. But I don't think the change is recent; it's certainly been around since I started learning scripting, and it seems first to have been noted in the lsl wiki back in January 2007: http://lslwiki.net/lslwiki/wakka.php?wakka=IfElse/show&time=2007-01-15+22:40:37 : I note this not out of historical interest but because it suggests you may be misdiagnosing the reason for your math error.

integer FA( integer a)
{
    if ( a ) llOwnerSay("FA is TRUE");
    else llOwnerSay("FA is FALSE");
    return a;
}

integer FB( integer b)
{
    if ( b ) llOwnerSay("FB is TRUE");
    else llOwnerSay("FB is FALSE");
    return b;
}

both( integer i)
{
    if ( i ) llOwnerSay("both are TRUE");
    else llOwnerSay("both are not TRUE\n");
}

default 
{
    touch_start(integer n)
    {
        both(FA(0) && FB(0));
        both(FA(0) && FB(1));
        both(FA(1) && FB(0));
        both(FA(1) && FB(1));
    }
}

When executed this test script gives following:
LSL Logic: FB is FALSE
LSL Logic: FA is FALSE
LSL Logic: both are not TRUE

LSL Logic: FB is TRUE
LSL Logic: FA is FALSE
LSL Logic: both are not TRUE

LSL Logic: FB is FALSE
LSL Logic: FA is TRUE
LSL Logic: both are not TRUE

LSL Logic: FB is TRUE
LSL Logic: FA is TRUE
LSL Logic: both are TRUE

This tells me that both A and B are executed no matter their logic values.
Still I would never rely on one or the other assumption.

The result is the same if compiled in MONO or not.

Wow, this is a huge and awesome help guys. I seriously don't know how I wasn't running into this issue more previously. All fixed now though! *grins*

Basically I was basing some code around the PNPoly idea.
http://www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html

As I said though, it really had seemed to work previously. Hope all goes well from here on out! Thanks again!