Steps to Reproduce

Run fiddle
http://zkfiddle.org/sample/1in4p18/5-Firefox-document-mouseUp-default

Click in the input in sequence 1 > 2 > 1 > 2 > 1 > 2 > ....
Note: there is a race condition between server reply and mouseUp.
To test for this issue, keep the mouse button down without moving the mouse until after the server replies arrive and the content is selected.
(on local / low latency, server reply will be received first)

Current Result

on half the clicks, the input will receive the selection, then loose selection on mouseUp because firefox will trigger caret positioning during mouseUp

Expected Result

Firefox should not affect selection during mouseup

Debug Info

Root Cause

Firefox native document-level onMouseUp listener

Workaround

prevent FF default mouseUp
deploy on zul page or globally with lang-addon

	<script><![CDATA[
zk.afterLoad('zul.inp', function() {
	var xInputWidget = {};
	zk.override(zul.inp.InputWidget.prototype, xInputWidget ,{
		doBlur_ : function() {
			var result = xInputWidget.doBlur_.apply(this, arguments);
			if(zk.ff){
				this.$n().selectionStart=0;
				this.$n().selectionEnd=0;
			}
			return result;
		}
	});//zk.override
});//zk.afterLoad
]]></script>