"port.sender.tab is undefined, can't access property "id" of it" in the browser console

This line in (main.js:55)…

verbose("send back the tab id", port.sender.tab.id);

…is periodically generating this error…

port.sender.tab is undefined, can't access property "id" of it

…in my browser console, which is distracting when I’m trying to debug other things.

If it’s indicative of a problem in CanvasBlocker, please fix it. Otherwise, if it’s spurious, please silence it.

Steps to Reproduce (for bugs)

I haven’t been able to reproduce it reliably. I think it’s some sort of race condition, since it seems to crop up most when a bug in another extension is causing the browser to bog down.

Context

It makes debugging other extensions more difficult, since it mostly crops up when something else is flooding the browser console with garbage and causing it to bog down.

Your Environment

• CanvasBlocker Version used: 0.5.3
• Firefox version incl. 32- or 64-bit: 63.0b4 (64-bit)
• Operating System and version (desktop or mobile): Kubuntu 14.04.5 LTS
• Installed addons:

Auto Tab Discard	0.2.8	true	{c2c003ee-bd69-42a2-b0e9-6f34222cb046}
Awesome RSS	1.3.4	true	{97d566da-42c5-4ef4-a03b-5a2e5f7cbcb2}
Behind The Overlay Revival	0.1.8	true	{c0e1baea-b4cb-4b62-97f0-278392ff8c37}
Bloody Vikings!	0.9.4	true	[e-mail]
CanvasBlocker	0.5.3	true	[e-mail]
Carefree Tumblr	0.1.0	true	{bb54be14-8b70-48a2-929b-2b26fa8bcca0}
Cookie AutoDelete	2.2.0	true	[e-mail]
cookies.txt	0.1	true	{12cf650b-1822-40aa-bff0-996df6948878}
Copy PlainText	1.8	true	[e-mail]
Decentraleyes	2.0.7	true	jid1-BoFifL9Vbdl2zQ@jetpack
Disable HTML5 Autoplay	2017.12.20	true	disable-html5-autoplay@afnankhan
Download Star	2.0.2	true	{8cc0b007-e40b-46e8-9e50-e3bf021c94ab}
File Backups	0.3.5	true	[e-mail]
Google search link fix	1.6.7	true	jid0-XWJxt5VvCXkKzQK99PhZqAn7Xbg@jetpack
Greasemonkey	4.7	true	{e4a8a97b-f2ed-450b-b12d-ee082ba24781}
HistoryBlock	2.0	true	historyblock@kain
HTTPS Everywhere	2018.8.22	true	[e-mail]
In-Page Pop-up Reporter	1.6	true	{feb799e2-29e2-4e35-b862-cc4e1842b6f5}
InlineDisposition Reloaded	2.0.1	true	{914d3a0b-6982-4e58-9a60-2e5d6cf6b09b}
Link Cleaner	1.5	true	{6d85dea2-0fb4-4de3-9f8c-264bce9a2296}
Multiple Tab Handler	2.1.4	true	[e-mail]
No Transition	1.1.8	true	{8b5fde66-c64d-4a33-99f1-c7c94138d67e}
Open in Sidebar	2018.7.26	true	open-link-in-sidebar@afnankhan
PinPatrol	0.4	true	@PinPatrol
Pure URL	1.3.0a	true	pure-url@jetpack
Random User-Agent	2.2.6	true	{b43b974b-1d3a-4232-b226-eaa2ac6ebb69}
Reload in address bar	1.3	true	{e1ed7a80-7c11-4f7e-968b-79b551a0067f}
Resurrect Pages	7	true	{0c8fbd76-bdeb-4c52-9b24-d587ce7b9dc3}
Select Link Text	2017.3.26	true	select-link-text@afnankhan
Session Boss	1.5	true	[e-mail]
Stylus	1.4.21	true	{7a7a4a92-a2a0-41d1-9fd7-1e92480d612d}
SuperStop	0.3	true	[e-mail]
Tab Count	1.0	true	[e-mail]
Tree Style Tab	2.5.4	true	[e-mail]
uBlock Origin	1.16.20	true	[e-mail]
uMatrix	1.3.14	true	[e-mail]
Unpaywall	3.77	true	{f209234a-76f0-4735-9920-eb62507a54cd}
Web ScrapBook	0.27.0	true	[e-mail]
Aggregate Tabs to Main Window	1.3.0	false	[e-mail]
cliget	2.0.0	false	[e-mail]
Form History Control (II)	2.2.0.0	false	[e-mail]
JSONovich	2.1.2	false	[e-mail]
Privacy Settings	0.3.4	false	jid1-CKHySAadH4nL6Q@jetpack
withExEditor	5.4.1	false	jid1-WiAigu4HIo0Tag@jetpack
YouTube Feeds	0.1.4	false	{e347026e-9666-402e-841e-20c9ec56c8ad}

(Sorry for the format. I just spent 15+ minutes waiting for Firefox to start responding after it seized up due to the bug in Form History Control that I was trying to diagnose when I encountered this error message and I don’t have the patience to manually fix up the tab stops.)

Your Settings

{
	"logLevel": 1,
	"urlSettings": [],
	"hiddenSettings": {},
	"displayHiddenSettings": false,
	"whiteList": "",
	"sessionWhiteList": "",
	"blackList": "",
	"blockMode": "fakeReadout",
	"minFakeSize": 1,
	"maxFakeSize": 0,
	"rng": "nonPersistent",
	"apiWhiteList": {},
	"useCanvasCache": true,
	"ignoreFrequentColors": 0,
	"minColors": 0,
	"fakeAlphaChannel": false,
	"persistentRndStorage": "",
	"persistentIncognitoRndStorage": "{}",
	"storePersistentRnd": false,
	"persistentRndClearIntervalValue": 0,
	"persistentRndClearIntervalUnit": "days",
	"lastPersistentRndClearing": 1536791621802,
	"askOnlyOnce": "combined",
	"askDenyMode": "block",
	"showCanvasWhileAsking": true,
	"showNotifications": true,
	"highlightPageAction": "none",
	"highlightBrowserAction": "color",
	"displayBadge": true,
	"storeImageForInspection": false,
	"notificationDisplayTime": 30,
	"ignoreList": "",
	"ignoredAPIs": {},
	"showCallingFile": false,
	"showCompleteCallingStack": false,
	"enableStackList": false,
	"stackList": "",
	"protectAudio": true,
	"audioFakeRate": "100",
	"audioNoiseLevel": "minimal",
	"useAudioCache": true,
	"audioUseFixedIndices": true,
	"audioFixedIndices": "16",
	"historyLengthThreshold": 2,
	"protectWindow": false,
	"blockDataURLs": true,
	"displayAdvancedSettings": true,
	"displayDescriptions": true,
	"theme": "default",
	"dontShowOptionsOnUpdate": false,
	"isStillDefault": false,
	"storageVersion": 0.3
}

[kkapsner]

I finally found a way to reproduce the problem. Just simply open the settings page over the toolbar popup.

[ssokolow]

Which Firefox are you using? They fixed this issue in Firefox nightly.

Firefox Developer Edition 63.0b7 (though it is also poking me to apply an update at the moment)