Investigate "ui is not defined"

[ianb]

In this Sentry report, probably related to #2902:

mousedown@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/selector/uicontrol.js:514:1
addHandlers/</fn<@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/selector/uicontrol.js:867:18
watchFunction/this.catcher@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/catcher.js:52:16
EventListener.handleEvent*installHandlersOnDocument@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/selector/uicontrol.js:888:7
display/this.ui</this.element.onload<@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/selector/ui.js:103:13
watchFunction/this.catcher@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/catcher.js:52:16
EventHandlerNonNull*display/this.ui<@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/selector/ui.js:95:33
display@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/selector/ui.js:81:14
display@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/selector/ui.js:323:14
start@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/selector/uicontrol.js:374:20
setState@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/selector/uicontrol.js:192:7
exports.activate@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/selector/uicontrol.js:821:7
this.uicontrol<@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/selector/uicontrol.js:924:3
@moz-extension://92b99b93-cd16-4545-acd7-cbb2387ae303/selector/uicontrol.js:6:19

It's in the mousedown event handler in the crosshairs state. This feels like it should have been fixed by #2942, but apparently was not.

[SoftVision-CosminMuntean]

I have observed that a "ReferenceError: ui is not defined" error is displayed in browser console if you save multiple shots consecutive on, but I am not sure if this is related or similar with the above error.

Here is a browser console error:

[ianb]

There's still an open issue, per this report:

Error: Error: Undefined ui in mousedown
mousedown@resource://screenshots-addon/selector/uicontrol.js:517:19
addHandlers/</fn<@resource://screenshots-addon/selector/uicontrol.js:884:18
watchFunction/this.catcher@resource://screenshots-addon/catcher.js:54:16

Probably the same underlying cleanup issue.

This report has a bigger traceback, but looks like the same thing.

[ianb]

Some more reports in the same category, but a little different:

• TypeError: this.element is null
• ReferenceError: shooter is not defined
• errorReferenceError: callBackground is not defined
• ReferenceError: assertIsTrusted is not defined

[jaredhirsch]

I think this should be fixed by #3222