{"action":"created","issue":{"url":"https://api.github.com/repos/facebook/react/issues/6098","repository_url":"https://api.github.com/repos/facebook/react","labels_url":"https://api.github.com/repos/facebook/react/issues/6098/labels{/name}","comments_url":"https://api.github.com/repos/facebook/react/issues/6098/comments","events_url":"https://api.github.com/repos/facebook/react/issues/6098/events","html_url":"https://github.com/facebook/react/issues/6098","id":135702702,"number":6098,"title":"warning in IE8 when ieCompatibilityMode is undefind","user":{"login":"jacty","id":4190959,"avatar_url":"https://avatars.githubusercontent.com/u/4190959?v=3","gravatar_id":"","url":"https://api.github.com/users/jacty","html_url":"https://github.com/jacty","followers_url":"https://api.github.com/users/jacty/followers","following_url":"https://api.github.com/users/jacty/following{/other_user}","gists_url":"https://api.github.com/users/jacty/gists{/gist_id}","starred_url":"https://api.github.com/users/jacty/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jacty/subscriptions","organizations_url":"https://api.github.com/users/jacty/orgs","repos_url":"https://api.github.com/users/jacty/repos","events_url":"https://api.github.com/users/jacty/events{/privacy}","received_events_url":"https://api.github.com/users/jacty/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/facebook/react/labels/Status:%20Unconfirmed","name":"Status: Unconfirmed","color":"d4c5f9"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":6,"created_at":"2016-02-23T10:51:52Z","updated_at":"2016-02-26T08:55:10Z","closed_at":null,"body":"I have read a snippet in the source of ReactDOM.js(as the 1st pic show).What I am confused about is:\r\n1.the document.documentMode's value is undefined in my IE8;\r\nwhat's more\r\n 2.when I was running React in my IE8's compatibility mode,got the errors ,like the 2nd pic show, without the warning about compatibilty mode. \r\n\r\nso may I know what is the meaning of this snippet and whether we should add some code to deal with the case I just suffered?\r\n![qq 20160223183504](https://cloud.githubusercontent.com/assets/4190959/13248943/38ef6504-da5c-11e5-915b-5be1bc77da6b.png)\r\n![qq 20160223183514](https://cloud.githubusercontent.com/assets/4190959/13248948/43cca5ea-da5c-11e5-8326-eb975d6dd6e4.png)\r\n"},"comment":{"url":"https://api.github.com/repos/facebook/react/issues/comments/189169361","html_url":"https://github.com/facebook/react/issues/6098#issuecomment-189169361","issue_url":"https://api.github.com/repos/facebook/react/issues/6098","id":189169361,"user":{"login":"spicyj","id":6820,"avatar_url":"https://avatars.githubusercontent.com/u/6820?v=3","gravatar_id":"","url":"https://api.github.com/users/spicyj","html_url":"https://github.com/spicyj","followers_url":"https://api.github.com/users/spicyj/followers","following_url":"https://api.github.com/users/spicyj/following{/other_user}","gists_url":"https://api.github.com/users/spicyj/gists{/gist_id}","starred_url":"https://api.github.com/users/spicyj/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/spicyj/subscriptions","organizations_url":"https://api.github.com/users/spicyj/orgs","repos_url":"https://api.github.com/users/spicyj/repos","events_url":"https://api.github.com/users/spicyj/events{/privacy}","received_events_url":"https://api.github.com/users/spicyj/received_events","type":"User","site_admin":false},"created_at":"2016-02-26T08:55:10Z","updated_at":"2016-02-26T08:55:10Z","body":"I don't know why that would be. You'll probably have to do more digging and figure out what's going on if you want this to be fixed since I haven't heard of anyone else hitting anything like this."}}