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
}
			}
		}		
	}	
	
	boolean isWrap(Control control) {
		if (control instanceof Composite
				&& ((Composite) control).getLayout() instanceof ILayoutExtension)
			return true;
		return (control.getStyle() & SWT.WRAP) != 0;
	}	
	private void initializeIfNeeded(Composite parent, boolean changed) {
		if (changed)
			initialLayout = true;
		if (initialLayout) {
			initializeLayoutData(parent);
			initialLayout = false;
		}
	}
	void initializeLayoutData(Composite composite) {
		Control[] children = composite.getChildren();
		for (int i = 0; i < children.length; i++) {
			Control child = children[i];
			if (child.getLayoutData() == null) {
				child.setLayoutData(new TableWrapData());
			}
		}
	}
}