Reproducible: always 1. Open New Tab Page 2. Open onboarding tour (click on top left button in the page) 3. Click on "Screenshots" menu in the left pane of onboarding tour panel 4. Click on [Open Screenshots Website] blue button at bottom right of the panel 5. Click on home toolbar button in nav bar Actual Results: "about: home" is shown instead of blank in location bar Expected Results: Location bar should be blank(i.e. only placeholder).

Error in browser console after step4: 05:16:40.707 this.widget is null 1 ext-browserAction.js:523 updateWindow chrome://browser/content/ext-browserAction.js:523:9 build/< chrome://browser/content/ext-browserAction.js:231:40 emit resource://gre/modules/ExtensionUtils.jsm:258:40 handleEvent chrome://browser/content/ext-browser.js:133:7 updateCurrentBrowser chrome://browser/content/tabbrowser.xml:1263:15 onselect chrome://browser/content/browser.xul:1:44 set_selectedIndex chrome://browser/content/tabbrowser.xml:8297:13 set_selectedPanel chrome://global/content/bindings/tabbox.xml:694:13 set_selectedIndex chrome://global/content/bindings/tabbox.xml:412:15 set_selectedItem chrome://global/content/bindings/tabbox.xml:444:34 set_selectedTab chrome://global/content/bindings/tabbox.xml:114:15 set_selectedTab chrome://browser/content/tabbrowser.xml:3716:11 loadOneTab chrome://browser/content/tabbrowser.xml:1694:15 _openURIInNewTab chrome://browser/content/browser.js:5221:15 browser_openURIInFrame chrome://browser/content/browser.js:5362:12

(In reply to Alice0775 White from comment #1) > Error in browser console after step4: > > 05:16:40.707 this.widget is null 1 ext-browserAction.js:523 > updateWindow chrome://browser/content/ext-browserAction.js:523:9 > build/< chrome://browser/content/ext-browserAction.js:231:40 > emit resource://gre/modules/ExtensionUtils.jsm:258:40 > handleEvent chrome://browser/content/ext-browser.js:133:7 > updateCurrentBrowser chrome://browser/content/tabbrowser.xml:1263:15 > onselect chrome://browser/content/browser.xul:1:44 > set_selectedIndex chrome://browser/content/tabbrowser.xml:8297:13 > set_selectedPanel chrome://global/content/bindings/tabbox.xml:694:13 > set_selectedIndex chrome://global/content/bindings/tabbox.xml:412:15 > set_selectedItem chrome://global/content/bindings/tabbox.xml:444:34 > set_selectedTab chrome://global/content/bindings/tabbox.xml:114:15 > set_selectedTab chrome://browser/content/tabbrowser.xml:3716:11 > loadOneTab chrome://browser/content/tabbrowser.xml:1694:15 > _openURIInNewTab chrome://browser/content/browser.js:5221:15 > browser_openURIInFrame chrome://browser/content/browser.js:5362:12 Filed Bug 1396438

(In reply to Alice0775 White from comment #0) > Reproducible: always > > 1. Open New Tab Page > 2. Open onboarding tour (click on top left button in the page) > 3. Click on "Screenshots" menu in the left pane of onboarding tour panel > 4. Click on [Open Screenshots Website] blue button at bottom right of the > panel > 5. Click on home toolbar button in nav bar > > Actual Results: > "about: home" is shown instead of blank in location bar > > Expected Results: > Location bar should be blank(i.e. only placeholder). Hi Alice, My test result is a below. Is yours the same? thanks # about:home case 1. Open about:home 2. Open onboarding tour (click on top left button in the page) 3. Click on "Screenshots" menu in the left pane of onboarding tour panel 4. Click on [Open Screenshots Website] blue button at bottom right of the panel 5. Click on home toolbar button in nav bar on the screenshots page opened in the step 4 6. The urlbal shows "about:home" # about:newtab case 1. Open about:newtab 2. Open onboarding tour (click on top left button in the page) 3. Click on "Screenshots" menu in the left pane of onboarding tour panel 4. Click on [Open Screenshots Website] blue button at bottom right of the panel 5. Click on home toolbar button in nav bar on the screenshots page opened in the step 4 6. The urlbal is blank

# about:home case same. # about:newtab case 6. The urlbar shows "about:home" instead 6. The urlbal is blank In both cases badly, 7. Open any web page(such as google) 8. The urlbar shows url as expected 9. Click on home toolbar button 10. The urlbar shows "about:home". the problem persists until the tab close.

(In reply to Alice0775 White from comment #4) > # about:home case > same. > > # about:newtab case > 6. The urlbar shows "about:home" > instead > 6. The urlbal is blank > > > In both cases badly, > 7. Open any web page(such as google) > 8. The urlbar shows url as expected > 9. Click on home toolbar button > 10. The urlbar shows "about:home". the problem persists until the tab close. Alright, that is weird. My result is not the same as yours. The issue only happens if we started on about:home. It would run normally if started on about:newtab # about:home case 1. Open about:home 2. Open onboarding tour (click on top left button in the page) 3. Click on "Screenshots" menu in the left pane of onboarding tour panel 4. Click on [Open Screenshots Website] blue button at bottom right of the panel 5. Click on home toolbar button in nav bar on the screenshots page opened in the step 4 6. The urlbal shows "about:home" 7. In the same tab open https://www.google.com 8. The urlbar shows "https://www.google.com" as expected 9. Click on home toolbar button 10. The urlbar shows "about:home" # about:newtab case 1. Open about:newtab 2. Open onboarding tour (click on top left button in the page) 3. Click on "Screenshots" menu in the left pane of onboarding tour panel 4. Click on [Open Screenshots Website] blue button at bottom right of the panel 5. Click on home toolbar button in nav bar on the screenshots page opened in the step 4 6. The urlbal is blank 7. In the same tab open https://www.google.com 8. The urlbar shows "https://www.google.com" as expected 9. Click on home toolbar button 10. The urlbal is blank

In my case, It happens in both about:home case and about:newtab case.