fix vuejs#539 v-if duplicate compile when a different truthy value is…

… set

src/directives/if.js

@@ -43,6 +43,11 @@ module.exports = {
  },
 
  insert: function () {
+ // avoid duplicate inserts, since update() can be
+ // called with different truthy values
+ if (this.decompile) {
+ return
+ }
  var vm = this.vm
  var frag = templateParser.clone(this.template)
  var decompile = this.linker(vm, frag)

test/unit/specs/directives/if_spec.js

@@ -145,6 +145,22 @@ if (_.inBrowser) {
  })
  })
 
+ it('v-if with different truthy values', function (done) {
+ var vm = new Vue({
+ el: el,
+ data: {
+ a: 1
+ },
+ template: '<div v-if="a">{{a}}</div>'
+ })
+ expect(el.innerHTML).toBe(wrap('<div>1</div>'))
+ vm.a = 2
+ _.nextTick(function () {
+ expect(el.innerHTML).toBe(wrap('<div>2</div>'))
+ done()
+ })
+ })
+
  it('invalid warn', function () {
  el.setAttribute('v-if', 'test')
  var vm = new Vue({