1640738 - TypeError: can't access property "canGoBack", this.webNavigation is null

Status: NEW

(Toolkit :: UI Widgets, defect)

Description

[[ex-Mozilla] Agi Sferro | :agi]

Lot's of these in Web platform tests (at least):

05-25 17:13:22.565  2791  2806 E GeckoConsole: [JavaScript Error: "TypeError: can't access property "canGoBack", this.webNavigation is null" {file: "chrome://global/content/elements/browser-custom-element.js" line: 426}]
05-25 17:13:22.565  2791  2806 E GeckoConsole: get canGoBack@chrome://global/content/elements/browser-custom-element.js:426:7
05-25 17:13:22.565  2791  2806 E GeckoConsole: onLocationChange@resource://gre/modules/GeckoViewNavigation.jsm:568:7
05-25 17:13:22.565  2791  2806 E GeckoConsole: _callProgressListeners@resource://gre/modules/RemoteWebProgress.jsm:75:31
05-25 17:13:22.565  2791  2806 E GeckoConsole: onLocationChange@resource://gre/modules/RemoteWebProgress.jsm:119:10
05-25 17:13:22.565  2791  2806 E GeckoConsole: [JavaScript Error: "RemoteWebProgress failed to call onLocationChange: [Exception... "[JavaScript Error: "can't access property "canGoBack", this.webNavigation is null" {file: "chrome://global/content/elements/browser-custom-element.js" line: 426}]'[JavaScript Error: "can't access property "canGoBack", this.webNavigation is null" {file: "chrome://global/content/elements/browser-custom-element.js" line: 426}]' when calling method: [nsIWebProgressListener::onLocationChange]"  nsresult: "0x80570021 (NS_ERROR_XPC_JAVASCRIPT_ERROR_WITH_DETAILS)"  location: "JS frame :: resource://gre/modules/RemoteWebProgress.jsm :: _callProgressListeners :: line 75"  data: yes]" {file: "resource://gre/modules/RemoteWebProgress.jsm" line: 78}]

e.g. https://firefoxci.taskcluster-artifacts.net/XbAsjr_rRveR6krKgnNCdg/0/public/test_info//logcat-emulator-5554.log