When a new tab page per-window theme is applied, and a tab is detached away from that window, the tab will still preserve the per-window theme, even though it should instead match the theme of the new window it is in.

Comment on attachment 8990024 [details] Bug 1473270 - Handle tab detaching for new tab page per-window themes. https://reviewboard.mozilla.org/r/255054/#review261944 This looks good! What are the chances we could write a test for it? Also, this bug should probably depend on bug 1347204, and not block it (since I imagine we'll want to land bug 1347204 first). ::: toolkit/modules/LightweightThemeConsumer.jsm:122 (Diff revision 1) > this._update(temp.LightweightThemeManager.currentThemeForDisplay); > > this._win.addEventListener("resolutionchange", this); > this._win.addEventListener("unload", this, { once: true }); > this._win.messageManager.addMessageListener("LightweightTheme:Request", this); > Let's put this with the other event listeners, above line 121. ::: toolkit/modules/LightweightThemeConsumer.jsm:167 (Diff revision 1) > this._update(this._lastData); > } > break; > case "unload": > Services.obs.removeObserver(this, "lightweight-theme-styling-update"); > this._win.removeEventListener("resolutionchange", this); I think we should remove the event handler here.

Pushed by ntim.bugs@gmail.com: https://hg.mozilla.org/integration/autoland/rev/9cf5aaf01772 Handle tab detaching for new tab page per-window themes. r=mconley

Is manual testing required on this bug? If yes, please provide the proper theme/addon, currently all tab themes I've tested work as expected on Nightly and do not change upon detaching, if manual testing is not needed please set the “qe-verify -“ flag. Thanks!

Bug 1473879 will provide automated tests for this.