Changed to !document.documentMode

[SchleyB]

Line 124 of ChangeEventPlugin.js

isInputEventSupported = isEventSupported('input') && (!('documentMode' in document) || document.documentMode > 11);

Is incorrectly returning false in non-IE browsers when paired with some 3rd party code, specifically

!('documentMode' in document)

Is returning false because 3rd party code is setting document.documentMode to undefined. This is causing these errors on input fields

Uncaught TypeError: activeElement.detachEvent is not a function
TypeError·Uncaught TypeError: Cannot delete property 'value' of #

A better check in this case is

!document.documentMode

As this would still accomplish the intended check while minimizing conflicts with other codebases

I have found a couple of other instances of this issue:
#7421
#5920

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[gaearon]

Have you verified that IE9 still works as intended?

[SchleyB]

Yes, the check is still correctly returning false in IE9

[aweary]

Seems good to me then 👍

[gaearon]

@aweary Please also set the milestone to 15-next so release manager sees the change. (I'm not sure if there is any case when this is unnecessary, @zpao might know.)

[gaearon]

Also, since contributors can’t commit, once you accept, you can merge.
When you merge docs you’ll need to put “needs merge to stable” label on it.

[aweary]

Thanks @gaearon, forgot to do that here 👍

[just-boris]

Just curious, but can anybody show me an evidence that Google Tag Manager changes the documentMode?

I have checked their script and have found only read from this property, but not set.

I am paying so much attention to this because it is not okay to blame for something, that he doesn't do actually.

[SchleyB]

@just-boris I thought that it was GTM in this case but I don't have direct evidence to support that so I went ahead and took that out of the original comment. Thanks