Bug 89824 [Forms] Position of Go button in Help Search view changes
If you expand and contract the Default Scope area the position of the Go button will shift (and the combo will shrink and grow). I will attach two screencaps - note the space to the right of the Go button.
bundles/org.eclipse.ui.forms/src/org/eclipse/ui/forms/widgets/TableWrapLayout.java
totalHeight = topMargin + innerHeight + bottomMargin;
		return new Point(tableWidth, totalHeight);
	}
	private void updateRowSpans(int row, int rowHeight) {
		if (rowspans == null || rowspans.size() == 0)
			return;
		for (Enumeration enm = rowspans.elements(); enm.hasMoreElements();) {
			RowSpan rowspan = (RowSpan) enm.nextElement();
			rowspan.update(row, rowHeight);
		}
	}
	private int compensateForRowSpans(int totalHeight) {
		for (Enumeration enm = rowspans.elements(); enm.hasMoreElements();) {
			RowSpan rowspan = (RowSpan) enm.nextElement();
			totalHeight += rowspan.getRequiredHeightIncrease();
		}
		return totalHeight;
	}
	int internalGetMinimumWidth(Composite parent, boolean changed) {
		if (changed)
			
			calculateColumnWidths(parent, minColumnWidths, false, true, makeColumnsEqualWidth);
		int minimumWidth = 0;
		widestColumnWidth = 0;
		if (makeColumnsEqualWidth) {
			for (int i = 0; i < numColumns; i++) {
				widestColumnWidth = Math.max(widestColumnWidth,
						minColumnWidths[i]);
			}
		}