1378081 - null return value from CustomizableUIInternal.normalizeWidget ignored in createWidget

Status: RESOLVED WONTFIX

(Firefox :: Toolbars and Customization, defect)

Description

[Pavel Studený]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36

Steps to reproduce:

After a bit of playing with UI customization and adding/reving an addon icon, it wasn't possible to see the icon anymore, even after reinstalling the addon.


Actual results:

unhandled exception

fileName:"resource://app/modules/CustomizableUI.jsm"
lineNumber:1230
message:"aId is undefined"
stack:"isSpecialWidget@resource://app/modules/CustomizableUI.jsm:1230:5
getWidgetProvider@resource://app/modules/CustomizableUI.jsm:851:9
wrapWidget@resource://app/modules/CustomizableUI.jsm:463:20
createWidget@resource://app/modules/CustomizableUI.jsm:3266:12
create@resource://gre/modules/commonjs/sdk/ui/button/view.js:122:3
setup@resource://gre/modules/commonjs/sdk/ui/button/toggle.js:61:5
@resource://gre/modules/commonjs/sdk/core/disposable.js:45:56
dispatch@resource://gre/modules/commonjs/method/core.js:119:12
initialize@resource://gre/modules/commonjs/sdk/core/disposable.js:135:17
constructor@resource://gre/modules/commonjs/sdk/core/heritage.js:146:23
[20]<@resource://jid1-r1tduninb4seww-at-jetpack/lib/main.js:13691:14
s@resource://jid1-r1tduninb4seww-at-jetpack/lib/main.js:1:245
e@resource://jid1-r1tduninb4seww-at-jetpack/lib/main.js:1:424
@resource://jid1-r1tduninb4seww-at-jetpack/lib/main.js:1:44
@resource://jid1-r1tduninb4seww-at-jetpack/lib/main.js:1:2
run@resource://gre/modules/commonjs/sdk/addon/runner.js:147:19
startup/</<@resource://gre/modules/commonjs/sdk/addon/runner.js:87:9
process@resource://gre/modules/Promise-backend.js:922:23
walkerLoop@resource://gre/modules/Promise-backend.js:806:7
scheduleWalkerLoop/<@resource://gre/modules/Promise-backend.js:742:11
"


Expected results:

at CustomizableUI.jsm,
  createWidget(aProperties) {
    return CustomizableUIInternal.wrapWidget(
      CustomizableUIInternal.createWidget(aProperties)
    );
  },
createWidget returns undefined because normalizeWidget has failed. This value is passeed with any failure checks to wrapWidget where it crashes. normalizeWidget can return null for a large number of reasons, out of them at least gPalette.has(widget.id) is valid and should be handled.

Comment 1

[Pavel Studený]

might be related to https://bugzilla.mozilla.org/show_bug.cgi?id=1273293

Comment 2

[:Gijs (he/him)]

Call destroyWidget before calling createWidget again. If the add-on sdk doesn't get this right and that's why things are broken, consider migrating to webextensions - I don't think we're going to be making any changes to the SDK before 57 when it'll be deprecated (given nightly is on 56 now).

In general, I don't really think making wrapWidget return null (which is presumably what you're expecting instead?) would make things better here - the sdk would just break with an uncaught exception a little later.