333475 - onkeydown preventDefault doesn't cancel keypress on Mac

Status: RESOLVED FIXED

(Core Graveyard :: Widget: Mac, defect)

Description

[Mark Mentovai]

On the Mac, an onkeydown event handler that calls event.preventDefault() does not suppress the keystroke from being handled in some situations.  In the testcase, a <div> with style display:none is shown in response to a keydown event, and an <input> contained therein is focused.  The event then has preventDefault called on it.

On Linux and Windows, the key pressed does not register any input in the now-focused <input> field.

On Mac, the key pressed causes a keypress to appear in the text field, even though the keydown handler called preventDefault.

I think we may have an open bug on this, but I can't find it.

Comment 1

[Mark Mentovai]

Attachment: Testcase

Open the testcase and press the 'z' key to unhide a <div> and focus an <input type="text"> that it contains.

Expected results: the 'z' is not added to the text field because preventDefault was called.

Observed results (on Mac): the 'z' is added to the text field.

The workaround clears the text field on a zero-duration timer after displaying the <div>.

Comment 2

[Jesse Ruderman]

This problem was mentioned in bug 333475.

Comment 3

[Mark Mentovai]

Of course it was!  Did you have another bug in mind?

Comment 4

[Jesse Ruderman]

Oops.  This problem was mentioned in bug 332561.

Comment 5

[Mark Mentovai]

I fixed this in bug 337199 after I rewrote the key event handlers.