949059 - "Return value is not an object." thrown when changing input in Contacts

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect)

Description

[Julien Wajsberg [:julienw]]

STR:
* launch the contacts app
* press "+" to add an ew contact
* type something in "name"
* tap the "Last name" entry
* have a look to the logcat

=> [JavaScript Error: "Return value is not an object."]

I debugged this with gdb with :bz and :padenot, and this traces to the "mgmt" property of MozInputMethod. See [1] for the full stack trace.

:bz thinks it could be related to the commit [2] (Bug 905573) because the implementation can return "null" in some situations ([3]) whereas the IDL wants an object.

I honestly don't know if there is a practical implication. The main issue is that it adds lines to the log, and since there is another issue (to be filed by :bz) we don't see the originating file, and this makes other bugs more difficult to debug.

[1] http://pastie.org/8545283
[2] http://hg.mozilla.org/mozilla-central/rev/20b30db87bf4
[3] http://hg.mozilla.org/mozilla-central/rev/20b30db87bf4#l2.206

Comment 1

[Boris Zbarsky [:bzbarsky]]

The practical issue is that doing .mgmt will throw in the situations in which the getter returns null.

If that's the desired behavior, the getter should instead be throwing, with a more informative error message than just "hey, you promised this wouldn't be null but returned null!".  But I expect it's not the desired behavior.

Comment 2

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

Attachment: patch v1

It's an implementation bug. The "mgmt" property of MozInputMethod should never be null.

Comment 3

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 8346061 [details] [diff] [review]
patch v1

Test, please!  ;)

Comment 4

[[:fabrice] Fabrice Desré]

Comment on attachment 8346061 [details] [diff] [review]
patch v1

Review of attachment 8346061 [details] [diff] [review]:
-----------------------------------------------------------------

r=me but as bz said, we need tests to land that.

Comment 5

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

@Fabrice, could you help me to land bug 932145?  So that I can write a test based on that bug.

Comment 6

[[:fabrice] Fabrice Desré]

Yep, I just reviewed it!

Comment 7

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

Attachment: patch v2 with mochitest

Add mochitest.
https://tbpl.mozilla.org/?tree=Try&rev=10ce31c5418a

Comment 8

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/integration/b2g-inbound/rev/ab453d9db208

Comment 9

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/ab453d9db208