Element.alignTo without arbitrary 5,5 addition to scrollX/Y

gistfile1.txt

        getAlignToXY : function(alignToEl, posSpec, offset) {
            alignToEl = Ext.get(alignToEl);

            if (!alignToEl || !alignToEl.dom) {
                //<debug>
                Ext.Error.raise({
                    sourceClass: 'Ext.dom.Element',
                    sourceMethod: 'getAlignToXY',
                    msg: 'Attempted to align an element that doesn\'t exist'
                });
                //</debug>
            }

            offset = offset || [0,0];
            posSpec = (!posSpec || posSpec == "?" ? "tl-bl?" : (!(/-/).test(posSpec) && posSpec !== "" ? "tl-" + posSpec : posSpec || "tl-bl")).toLowerCase();

            var me = this,
                    myPosition,
                    alignToElPosition,
                    x,
                    y,
                    myWidth,
                    myHeight,
                    alignToElRegion,
                    viewportWidth = Ext.dom.Element.getViewWidth() - 10, // 10px of margin for ie
                    viewportHeight = Ext.dom.Element.getViewHeight() - 10, // 10px of margin for ie
                    p1y,
                    p1x,
                    p2y,
                    p2x,
                    swapY,
                    swapX,
                    docElement = doc.documentElement,
                    docBody = doc.body,
                    scrollX = (docElement.scrollLeft || docBody.scrollLeft || 0),// + 5, WHY was 5 ever added?
                    scrollY = (docElement.scrollTop  || docBody.scrollTop  || 0),// + 5, It means align will fail if the alignTo el was at less than 5,5
                    constrain, //constrain to viewport
                    align1,
                    align2,
                    alignMatch = posSpec.match(alignRe);

            if (!alignMatch) {
                //<debug>
                Ext.Error.raise({
                    sourceClass: 'Ext.dom.Element',
                    sourceMethod: 'getAlignToXY',
                    el: alignToEl,
                    position: posSpec,
                    offset: offset,
                    msg: 'Attemmpted to align an element with an invalid position: "' + posSpec + '"'
                });
                //</debug>
            }

            align1 = alignMatch[1];
            align2 = alignMatch[2];
            constrain = !!alignMatch[3];

            //Subtract the aligned el's internal xy from the target's offset xy
            //plus custom offset to get this Element's new offset xy
            myPosition = me.getAnchorXY(align1, true);
            alignToElPosition = alignToEl.getAnchorXY(align2, false);

            x = alignToElPosition[0] - myPosition[0] + offset[0];
            y = alignToElPosition[1] - myPosition[1] + offset[1];

            // If position spec ended with a "?", then constrain to viewport is necessary
            if (constrain) {
                myWidth = me.getWidth();
                myHeight = me.getHeight();
                alignToElRegion = alignToEl.getRegion();
                //If we are at a viewport boundary and the aligned el is anchored on a target border that is
                //perpendicular to the vp border, allow the aligned el to slide on that border,
                //otherwise swap the aligned el to the opposite border of the target.
                p1y = align1.charAt(0);
                p1x = align1.charAt(align1.length - 1);
                p2y = align2.charAt(0);
                p2x = align2.charAt(align2.length - 1);
                swapY = ((p1y == "t" && p2y == "b") || (p1y == "b" && p2y == "t"));
                swapX = ((p1x == "r" && p2x == "l") || (p1x == "l" && p2x == "r"));

                if (x + myWidth > viewportWidth + scrollX) {
                    x = swapX ? alignToElRegion.left - myWidth : viewportWidth + scrollX - myWidth;
                }
                if (x < scrollX) {
                    x = swapX ? alignToElRegion.right : scrollX;
                }
                if (y + myHeight > viewportHeight + scrollY) {
                    y = swapY ? alignToElRegion.top - myHeight : viewportHeight + scrollY - myHeight;
                }
                if (y < scrollY) {
                    y = swapY ? alignToElRegion.bottom : scrollY;
                }
            }
            return [x,y];
        },