{"action":"opened","issue":{"url":"https://api.github.com/repos/vuejs/vue/issues/5838","repository_url":"https://api.github.com/repos/vuejs/vue","labels_url":"https://api.github.com/repos/vuejs/vue/issues/5838/labels{/name}","comments_url":"https://api.github.com/repos/vuejs/vue/issues/5838/comments","events_url":"https://api.github.com/repos/vuejs/vue/issues/5838/events","html_url":"https://github.com/vuejs/vue/issues/5838","id":234114981,"number":5838,"title":"TypeError: Cannot read property 'key' of undefined","user":{"login":"valeriob","id":1522516,"avatar_url":"https://avatars1.githubusercontent.com/u/1522516?v=3","gravatar_id":"","url":"https://api.github.com/users/valeriob","html_url":"https://github.com/valeriob","followers_url":"https://api.github.com/users/valeriob/followers","following_url":"https://api.github.com/users/valeriob/following{/other_user}","gists_url":"https://api.github.com/users/valeriob/gists{/gist_id}","starred_url":"https://api.github.com/users/valeriob/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/valeriob/subscriptions","organizations_url":"https://api.github.com/users/valeriob/orgs","repos_url":"https://api.github.com/users/valeriob/repos","events_url":"https://api.github.com/users/valeriob/events{/privacy}","received_events_url":"https://api.github.com/users/valeriob/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":0,"created_at":"2017-06-07T07:21:28Z","updated_at":"2017-06-07T07:21:28Z","closed_at":null,"body":"### Version\r\n2.3.0\r\n\r\n### Reproduction link\r\n[https://jsfiddle.net/superboy2k/50wL7mdz/38665/](https://jsfiddle.net/superboy2k/50wL7mdz/38665/)\r\n\r\n### Steps to reproduce\r\nClick Init, Click Update a few times, click Add => see the error  in the console\r\n\r\n### What is expected?\r\nto update the ui correctly\r\n\r\n### What is actually happening?\r\nTypeError: Cannot read property 'key' of undefined\r\n    at sameVnode (unpkg.com/vue@2.3.3:4769)\r\n    at updateChildren (unpkg.com/vue@2.3.3:5128)\r\n    at patchVnode (unpkg.com/vue@2.3.3:5180)\r\n    at updateChildren (unpkg.com/vue@2.3.3:5096)\r\n    at patchVnode (unpkg.com/vue@2.3.3:5180)\r\n    at updateChildren (unpkg.com/vue@2.3.3:5096)\r\n    at patchVnode (unpkg.com/vue@2.3.3:5180)\r\n    at Vue$3.patch [as __patch__] (unpkg.com/vue@2.3.3:5305)\r\n    at Vue$3.Vue._update (unpkg.com/vue@2.3.3:2327)\r\n    at Vue$3.updateComponent (unpkg.com/vue@2.3.3:2443)\r\n\r\n<!-- generated by vue-issues. DO NOT REMOVE -->"}}
{"actor":{"display_login":"valeriob"}}