904224 - "System JS : ERROR chrome://browser/content/forms.js:827 TypeError: element is null" in green B2G mochitest-2,3 runs

Status: RESOLVED FIXED

(Firefox OS Graveyard :: Gaia::Keyboard, defect)

Description

[Ryan VanderMeulen [:RyanVM]]

+++ This bug was initially created as a clone of Bug #902168 +++

Yuan, it appears that you are the primary maintainer of forms.js. Can you please investigate this? This and bug 902168 are VERY spammy (as you can see in the logs linked below).

https://tbpl.mozilla.org/php/getParsedLog.php?id=26445003&tree=B2g-Inbound
https://tbpl.mozilla.org/php/getParsedLog.php?id=26447273&tree=B2g-Inbound

Comment 1

[[:fabrice] Fabrice Desré]

Attachment: patch

Simple fix to bail out cleanly. We may need to fix the underlying issue but in any case getContentEditableText() needed to be a bit more robust.

Comment 2

[[:fabrice] Fabrice Desré]

https://hg.mozilla.org/integration/b2g-inbound/rev/f32a0cec5e80

Comment 3

[Yuan Xulei [:yxl] (Leave from May 18)]

Hi Fabrice,

the root cause is that we assume that key events of B2G are all generated by the virtual keyboard. As when virtual keyboard shows, the element is the current focus input element and won't be null, we don't check the element value. But in this case, we don't have a virtual keyboard and a focus input element. When 'keydown' events are generated, forms.js tries to update the selection info of the `focused element` and get `focused element is null` error.

Comment 4

[Yuan Xulei [:yxl] (Leave from May 18)]

Attachment: Don't handle key events in forms.js if these is no focused input element.

Comment 5

[Yuan Xulei [:yxl] (Leave from May 18)]

Fabrice, thanks.

Mark as checkin-needed.

Comment 6

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/integration/b2g-inbound/rev/b7fb2433a75f

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/f32a0cec5e80
https://hg.mozilla.org/mozilla-central/rev/b7fb2433a75f