User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:55.0) Gecko/20100101 Firefox/55.0 Build ID: 20170525030225 Steps to reproduce: 0. Download and unzip the attachment somewhere on your disk 1. Create a new profile 2. Start Firefox 3. double click on Index.html file (So that index.html opens in a new tab) Actual results: Intermittently, the new tab wont show anything. It is completely blank. However, if you move your mouse inside the page, the cursor will behave as if there is content in the page. (For the attachment, mouse pointer becomes the "hand" pointer). The moise will show tooltips etc. The only way to show content is to detach the tab from the window. This will cause the page to " become visible" Expected results: not so Tentatively, this is a regression from bug 132866

mouse inside the window shows the tooltips, and the pointer looks like a hand-pointer

Here, i am dragging the tab. The tab-drag-preview shows the outline of the page.

I meant bug 1362866 tentative ni?

This is on Windows10x64 And this bug is not restricted to opening a locally stored file. I reproduced it with a Pushbullet notification that opens a URL in a new background tab

(In reply to Mayank Bansal from comment #1) > Created attachment 8871585 [details] > part1.png > > mouse inside the window shows the tooltips, and the pointer looks like a > hand-pointer Which essentially means that the page has successfully loaded with all the JS/CSS etc, it is just not visible.

100% Reproducible STR: 0. Download and unzip the attachment somewhere on your disk 1. Create a new profile 2. Start Firefox 2.5 Minimize the nightly window (by clicking on the minimize button on the top right corner, the usual method to minimize any window on Windows) 3. double click on Index.html file (So that index.html opens in a new tab) ER: HTML page is rendered AR: Blank page until you detach the tab, and then attach it back

In fact, you dont need any fancy HTML page. This html is enough to reproduce the issue

confirmed by Mozregression: 6:54.15 INFO: Last good revision: 6d4744a6c81c498cc81cad11b4ead64660a3d269 6:54.15 INFO: First bad revision: aa48bb3f494410de514041e8c06ca15c38680181 6:54.15 INFO: Pushlog: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=6d4744a6c81c498cc81cad11b4ead64660a3d269&tochange=aa48bb3f494410de514041e8c06ca15c38680181 6:56.82 INFO: Looks like the following bug has the changes which introduced the regression: https://bugzilla.mozilla.org/show_bug.cgi?id=1362866

The index.html file from the rar file.

Comment on attachment 8871828 [details] index.html Bah, apparently, the page depends on the other files in the rar.

I've recompressed the files in dd.rar into dd.zip so that I don't have to install another archiving tool on my desktop machine.

As I said in comment 7, any HTML file will do. This is reproducible with title.html also (attached last)

No luck reproducing this on my Windows machines. :( Mayank Bansal, can you do me a favour, and create the new bool pref in about:config: browser.tabs.remote.logSwitchTiming and set it to true and then restart, and reproduce the issue. Once reproduced, can you then open the Browser Console via Ctrl-Shift-J, and paste me its contents?

See comment 6 for 100% repro STR (for me, anyway) (I did a bunch of stuff while getting the log. relevant output should be near the end. File loaded is called "title.html" ) *********************************************Output****************************************** 5/26/2017, 10:12:10 PM - Signed in with API key tjkqiXaJxd6dCBC56OHTZgmbFZrIgVUj pb.js:39:9 5/26/2017, 10:12:10 PM - Bootstrapping... pb.js:39:9 5/26/2017, 10:12:10 PM - Connecting to server via WebSocket pb.js:39:9 5/26/2017, 10:12:11 PM - Dismissed e2e pb.js:39:9 5/26/2017, 10:12:13 PM - WebSocket onopen pb.js:39:9 "5/26/2017, 10:12:13 PM - POST https://api.pushbullet.com/v2/sync" pb.js:39:9 5/26/2017, 10:12:13 PM - Received message: pb.js:39:9 Object { type: "nop" } pb.js:39:9 5/26/2017, 10:12:14 PM - Saving pushes pb.js:39:9 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:5:18068 Unknown property ‘-moz-border-radius’. Declaration dropped. search:5:18272 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:5:19514 Unknown property ‘-moz-border-radius’. Declaration dropped. search:5:19677 Expected color but found ‘top’. Error in parsing value for ‘background’. Declaration dropped. search:5:20071 Expected ‘none’, URL, or filter function but found ‘progid’. Error in parsing value for ‘filter’. Declaration dropped. search:5:20099 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:5:20257 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:5:20346 Expected color but found ‘top’. Error in parsing value for ‘background’. Declaration dropped. search:5:20517 Expected ‘none’, URL, or filter function but found ‘progid’. Error in parsing value for ‘filter’. Declaration dropped. search:5:20545 Expected end of value but found ‘main-size’. Error in parsing value for ‘flex’. Declaration dropped. search:5:22638 Expected media feature name but found ‘-webkit-min-device-pixel-ratio’. search:5:22951 Expected media feature name but found ‘min-device-pixel-ratio’. search:5:22989 Expected end of value but found ‘main-size’. Error in parsing value for ‘flex’. Declaration dropped. search:5:23333 Expected end of value but found ‘main-size’. Error in parsing value for ‘flex’. Declaration dropped. search:5:23462 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:5:23943 Expected end of value but found ‘main-size’. Error in parsing value for ‘flex’. Declaration dropped. search:5:24701 Expected end of value but found ‘0’. Error in parsing value for ‘-moz-box-flex’. Declaration dropped. search:5:25374 Unknown pseudo-class or pseudo-element ‘-webkit-scrollbar’. Ruleset ignored due to bad selector. search:5:25464 Unknown pseudo-class or pseudo-element ‘-webkit-scrollbar-button’. Ruleset ignored due to bad selector. search:5:25514 Unknown pseudo-class or pseudo-element ‘-webkit-scrollbar-thumb’. Ruleset ignored due to bad selector. search:5:25565 Unknown pseudo-class or pseudo-element ‘-webkit-scrollbar-thumb’. Ruleset ignored due to bad selector. search:5:25782 Expected media feature name but found ‘-o-min-device-pixel-ratio’. search:6:338 Expected media feature name but found ‘-webkit-min-device-pixel-ratio’. search:6:370 Expected media feature name but found ‘min-device-pixel-ratio’. search:6:408 Expected media feature name but found ‘-o-min-device-pixel-ratio’. search:7:340 Expected media feature name but found ‘-webkit-min-device-pixel-ratio’. search:7:372 Expected media feature name but found ‘min-device-pixel-ratio’. search:7:410 Error in parsing value for ‘-moz-transition’. Declaration dropped. search:8:4122 Unknown property ‘user-select’. Declaration dropped. search:8:4395 Unknown property ‘-moz-text-overflow’. Declaration dropped. search:8:4939 Unknown property ‘-moz-border-radius’. Declaration dropped. search:8:8995 Unknown property ‘-moz-border-radius’. Declaration dropped. search:8:9298 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:8:9728 Unknown property ‘-moz-border-radius’. Declaration dropped. search:8:9821 Unknown property ‘-moz-border-radius’. Declaration dropped. search:8:9941 Expected color but found ‘top’. Error in parsing value for ‘background-image’. Declaration dropped. search:8:10157 Expected color but found ‘top’. Error in parsing value for ‘background-image’. Declaration dropped. search:8:10376 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:8:10675 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:8:10816 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:8:10956 Expected color but found ‘top’. Error in parsing value for ‘background-image’. Declaration dropped. search:8:11193 Expected color but found ‘top’. Error in parsing value for ‘background-image’. Declaration dropped. search:8:11385 Expected color but found ‘top’. Error in parsing value for ‘background-image’. Declaration dropped. search:8:11576 Expected color but found ‘top’. Error in parsing value for ‘background-image’. Declaration dropped. search:8:11763 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:8:11799 Expected color but found ‘top’. Error in parsing value for ‘background-image’. Declaration dropped. search:8:12010 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:8:12046 Expected color but found ‘top’. Error in parsing value for ‘background-image’. Declaration dropped. search:8:12260 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:8:12315 Unknown property ‘-moz-border-radius’. Declaration dropped. search:8:12798 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:8:13053 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:8:13209 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:8:15180 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:8:15781 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:8:18201 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:8:18368 Unknown property ‘-moz-tap-highlight-color’. Declaration dropped. search:47:4765 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:47:5799 Unknown property ‘-moz-tap-highlight-color’. Declaration dropped. search:47:72 Unknown property ‘tap-highlight-color’. Declaration dropped. search:47:106 Unknown property ‘zoom’. Declaration dropped. search Error in parsing value for ‘display’. Declaration dropped. search:53:2603 Unknown property ‘-moz-order’. Declaration dropped. search:53:2663 Unknown property ‘-moz-tap-highlight-color’. Declaration dropped. search:53:8931 Unknown pseudo-class or pseudo-element ‘-moz-autofill’. Ruleset ignored due to bad selector. search:53:11327 Error in parsing value for ‘display’. Declaration dropped. search:53:14110 Unknown property ‘-moz-tap-highlight-color’. Declaration dropped. search:53:18747 Unknown property ‘tap-highlight-color’. Declaration dropped. search:53:18781 Unknown property ‘-moz-tap-highlight-color’. Declaration dropped. search:54:1104 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:718 Expected color but found ‘top’. Error in parsing value for ‘background’. Declaration dropped. search:369:888 Expected ‘none’, URL, or filter function but found ‘progid’. Error in parsing value for ‘filter’. Declaration dropped. search:369:916 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:1045 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:1137 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:1259 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:1430 Expected color but found ‘top’. Error in parsing value for ‘background’. Declaration dropped. search:369:1601 Expected ‘none’, URL, or filter function but found ‘progid’. Error in parsing value for ‘filter’. Declaration dropped. search:369:1629 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:2808 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:2912 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:3028 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:3198 Unknown property ‘-moz-border-radius’. Declaration dropped. search:369:3531 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:3648 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:3807 Expected color but found ‘top’. Error in parsing value for ‘background’. Declaration dropped. search:369:3970 Expected ‘none’, URL, or filter function but found ‘progid’. Error in parsing value for ‘filter’. Declaration dropped. search:369:3998 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:4134 Expected color but found ‘top’. Error in parsing value for ‘background’. Declaration dropped. search:369:4506 Expected ‘none’, URL, or filter function but found ‘progid’. Error in parsing value for ‘filter’. Declaration dropped. search:369:4534 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:4665 Unknown property ‘-moz-border-radius’. Declaration dropped. search:369:5564 Unknown property ‘-moz-border-radius’. Declaration dropped. search:369:7013 Expected media feature name but found ‘-webkit-min-device-pixel-ratio’. search:369:8093 Expected media feature name but found ‘min-device-pixel-ratio’. search:369:8131 Expected color but found ‘top’. Error in parsing value for ‘background-image’. Declaration dropped. search:369:9784 Unknown property ‘-moz-border-radius’. Declaration dropped. search:369:9916 Expected ‘none’, URL, or filter function but found ‘progid’. Error in parsing value for ‘filter’. Declaration dropped. search:369:10029 Expected color but found ‘top’. Error in parsing value for ‘background-image’. Declaration dropped. search:369:10288 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:10487 Expected ‘none’, URL, or filter function but found ‘progid’. Error in parsing value for ‘filter’. Declaration dropped. search:369:10521 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:10683 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:11186 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:11583 Unknown property ‘-moz-border-radius’. Declaration dropped. search:369:11905 Unknown property ‘-moz-border-radius’. Declaration dropped. search:369:12359 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:12397 Error in parsing value for ‘width’. Declaration dropped. search:369:13829 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:14244 Unknown property ‘-moz-border-radius’. Declaration dropped. search:369:14552 Unknown property ‘-moz-box-shadow’. Declaration dropped. search:369:14590 Expected media feature name but found ‘-webkit-min-device-pixel-ratio’. search:369:16983 Expected media feature name but found ‘min-device-pixel-ratio’. search:369:17021 Expected media feature name but found ‘-webkit-min-device-pixel-ratio’. search:369:17381 Expected media feature name but found ‘min-device-pixel-ratio’. search:369:17419 Error: When not using *.example.org wildcard, the string supplied is expected to be either an exact URL to match or a URL prefix. The provided string ('firefoxux.github.io') is unlikely to match any pages. match-pattern.js:46:15 Expected declaration but found ‘*’. Skipped to next declaration. 87f46ba9c3d9ec1891ddddb29887590f.css:2:1157 Expected declaration but found ‘*’. Skipped to next declaration. 87f46ba9c3d9ec1891ddddb29887590f.css:2:1179 Unknown property ‘zoom’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:2:4989 Expected ‘none’, URL, or filter function but found ‘alpha(’. Error in parsing value for ‘filter’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:2:5232 Expected declaration but found ‘*’. Skipped to next declaration. 87f46ba9c3d9ec1891ddddb29887590f.css:2:6607 Expected declaration but found ‘*’. Skipped to next declaration. 87f46ba9c3d9ec1891ddddb29887590f.css:2:6639 Expected ‘none’, URL, or filter function but found ‘Alpha(’. Error in parsing value for ‘filter’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:20:515 Unknown property ‘user-select’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:20:2116 Expected ‘none’, URL, or filter function but found ‘alpha(’. Error in parsing value for ‘filter’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:20:12171 Expected ‘none’, URL, or filter function but found ‘Alpha(’. Error in parsing value for ‘filter’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:20:18292 Expected ‘none’, URL, or filter function but found ‘Alpha(’. Error in parsing value for ‘filter’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:20:18442 Expected ‘none’, URL, or filter function but found ‘Alpha(’. Error in parsing value for ‘filter’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:20:18517 Expected ‘none’, URL, or filter function but found ‘Alpha(’. Error in parsing value for ‘filter’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:20:29160 Expected ‘none’, URL, or filter function but found ‘Alpha(’. Error in parsing value for ‘filter’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:22:515 Unknown property ‘user-select’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:22:2116 Expected ‘none’, URL, or filter function but found ‘alpha(’. Error in parsing value for ‘filter’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:22:12171 Expected ‘none’, URL, or filter function but found ‘Alpha(’. Error in parsing value for ‘filter’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:24:2878 Expected ‘none’, URL, or filter function but found ‘Alpha(’. Error in parsing value for ‘filter’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:24:3028 Expected ‘none’, URL, or filter function but found ‘Alpha(’. Error in parsing value for ‘filter’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:24:3103 Expected ‘none’, URL, or filter function but found ‘Alpha(’. Error in parsing value for ‘filter’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:24:13746 Unknown property ‘-moz-box-shadow’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:26:223 Unknown property ‘user-select’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:26:571 Unknown property ‘user-select’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:26:808 Unknown property ‘-moz-box-shadow’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:32:4598 Unknown property ‘-moz-box-shadow’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:32:14268 Unknown property ‘-moz-box-shadow’. Declaration dropped. 87f46ba9c3d9ec1891ddddb29887590f.css:32:14862 Expected color but found ‘border’. Error in parsing value for ‘text-decoration’. Declaration dropped. show_bug.cgi:1:1377 Unknown property ‘-moz-border-radius’. Declaration dropped. show_bug.cgi:1:1679 Expected color but found ‘-moz-use-text-color’. Error in parsing value for ‘border-color’. Declaration dropped. show_bug.cgi:1:3474 Unknown property ‘-moz-border-radius’. Declaration dropped. show_bug.cgi:1:5135 Unknown property ‘-moz-border-radius’. Declaration dropped. show_bug.cgi:1:5429 Unknown property ‘-moz-border-radius’. Declaration dropped. show_bug.cgi:1:6181 Unknown property ‘-moz-border-radius’. Declaration dropped. show_bug.cgi:1:6793 Unknown property ‘-moz-box-shadow’. Declaration dropped. show_bug.cgi:1:7030 5/26/2017, 10:12:40 PM - Not reporting alive from dev installation pb.js:39:9 Object { name: "alive", signed_in: true, language: "en-US", clipboard_sync: false, e2e_enabled: false } analytics.js:8:9 Error in parsing value for ‘width’. Declaration dropped. show_bug.cgi 5/26/2017, 10:12:43 PM - Received message: pb.js:39:9 Object { type: "nop" } pb.js:39:9 START requestTab 1(about:blank) 0:VR(-) 1:(-) Tab should be blank: true Requested tab is remote?: true Switch to tab 1 - 1(about:blank) DEBUG: tab switch time = 7 FINISH done 0:(-) 1:VRB(-) Use of nsIFile in content process is deprecated. loader.js:247:15 Error: When not using *.example.org wildcard, the string supplied is expected to be either an exact URL to match or a URL prefix. The provided string ('firefoxux.github.io') is unlikely to match any pages. match-pattern.js:46:15 The character encoding of the HTML document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the page must be declared in the document or in the transfer protocol. title.html Key event not available on some keyboard layouts: key=“r” modifiers=“accel,alt” id=“key_toggleReaderMode” browser.xul Key event not available on some keyboard layouts: key=“i” modifiers=“accel,alt,shift” id=“key_browserToolbox” browser.xul Property contained reference to invalid variable. Error in parsing value for ‘background-color’. Falling back to ‘initial’. webconsole.css:406:9402 Property contained reference to invalid variable. Error in parsing value for ‘border-top-color’. Falling back to ‘initial’. webconsole.css:407:9459 Property contained reference to invalid variable. Error in parsing value for ‘border-top-style’. Falling back to ‘initial’. webconsole.css:407:9459 Property contained reference to invalid variable. Error in parsing value for ‘border-top-width’. Falling back to ‘initial’. webconsole.css:407:9459 Property contained reference to invalid variable. Error in parsing value for ‘background-image’. Falling back to ‘initial’. webconsole.css:444:10354 Property contained reference to invalid variable. Error in parsing value for ‘border-bottom-width’. Falling back to ‘initial’. widgets.css:85:2908 Property contained reference to invalid variable. Error in parsing value for ‘border-top-width’. Falling back to ‘initial’. widgets.css:84:2850 Property contained reference to invalid variable. Error in parsing value for ‘min-height’. Falling back to ‘initial’. widgets.css:82:2742 Property contained reference to invalid variable. Error in parsing value for ‘margin-bottom’. Falling back to ‘initial’. widgets.css:87:3041 Property contained reference to invalid variable. Error in parsing value for ‘margin-top’. Falling back to ‘initial’. widgets.css:86:2972 5/26/2017, 10:13:13 PM - Received message: pb.js:39:9 Object { type: "nop" } pb.js:39:9 START Initial tab is loaded?: true requestTab 0(https://bugzilla.mozilla.org/show_bug.cgi?id=1367964) 0:(-) 1:VR(+) Loading tab 0(https://bugzilla.mozilla.org/show_bug.cgi?id=1367964) Tab should be blank: false Requested tab is remote?: true done 0:LR(+?) 1:V(+) onLayersReady(0, true) 0:LR(+?) 1:V(+) DEBUG: tab switch time = 33 Tab should be blank: false Requested tab is remote?: true Switch to tab 0 - 0(https://bugzilla.mozilla.org/show_bug.cgi?id=1367964) done 0:VR(+) 1:(+) Tab should be blank: false Requested tab is remote?: true done 0:VR(+) 1:(+) Tab should be blank: false Requested tab is remote?: true done 0:VR(+) 1:(+) Tab should be blank: false Requested tab is remote?: true done 0:VR(+) 1:(+) onUnloadTimeout 0:VR(+) 1:(+) Tab should be blank: false Requested tab is remote?: true done 0:VR(+) 1:(-?) onLayersCleared(1) 0:VR(+) 1:(-?) Tab should be blank: false Requested tab is remote?: true FINISH done 0:VR(+) 1:(-) TypeError: parentDocShell.getDocShellEnumerator is not a function[Learn More] tab.js:62:23 START Initial tab is loaded?: true requestTab 1(file:///C:/Users/Mayank/Desktop/dd/title.html) 0:VR(+) 1:(-) Loading tab 1(file:///C:/Users/Mayank/Desktop/dd/title.html) Tab should be blank: false Requested tab is remote?: true done 0:V(+) 1:LR(+?) onLayersReady(1, true) 0:V(+) 1:LR(+?) DEBUG: tab switch time = 28 Tab should be blank: false Requested tab is remote?: true Switch to tab 1 - 1(file:///C:/Users/Mayank/Desktop/dd/title.html) done 0:(+) 1:VR(+) Tab should be blank: false Requested tab is remote?: true done 0:(+) 1:VR(+) Tab should be blank: false Requested tab is remote?: true done 0:(+) 1:VR(+) Tab should be blank: false Requested tab is remote?: true done 0:(+) 1:VR(+) onUnloadTimeout 0:(+) 1:VR(+) Tab should be blank: false Requested tab is remote?: true done 0:(-?) 1:VR(+) onLayersCleared(0) 0:(-?) 1:VR(+) Tab should be blank: false Requested tab is remote?: true FINISH done 0:(-) 1:VR(+) 5/26/2017, 10:13:43 PM - Received message: pb.js:39:9 Object { type: "nop" } pb.js:39:9

Thanks Mayank Bansal. Here's the relevant part of the log: START Initial tab is loaded?: true requestTab 1(file:///C:/Users/Mayank/Desktop/dd/title.html) 0:VR(+) 1:(-) Loading tab 1(file:///C:/Users/Mayank/Desktop/dd/title.html) Tab should be blank: false Requested tab is remote?: true done 0:V(+) 1:LR(+?) onLayersReady(1, true) 0:V(+) 1:LR(+?) DEBUG: tab switch time = 28 Tab should be blank: false Requested tab is remote?: true Switch to tab 1 - 1(file:///C:/Users/Mayank/Desktop/dd/title.html) done 0:(+) 1:VR(+) Tab should be blank: false Requested tab is remote?: true done 0:(+) 1:VR(+) Tab should be blank: false Requested tab is remote?: true done 0:(+) 1:VR(+) Tab should be blank: false Requested tab is remote?: true done 0:(+) 1:VR(+) onUnloadTimeout 0:(+) 1:VR(+) Tab should be blank: false Requested tab is remote?: true done 0:(-?) 1:VR(+) onLayersCleared(0) 0:(-?) 1:VR(+) Tab should be blank: false Requested tab is remote?: true FINISH So here, we're attempting to select tab 1 (title.html), and we determine that the tab should not be blank and that it's remote... 28ms later, we get its layers sent up, and we apparently complete the switch. We then unload the first tab, and we're done. Are you _absolutely_ sure that you cannot reproduce this before bug 1362866 landed? Because at least according to the log, in the tab switch where you experienced the bug, we didn't even do any of the "blanking" stuff that bug 1362866 introduced. If you _are_ able to reproduce this in a build from before bug 1362866 landed, this sounds a lot like bug 1364563 to me.

can you point me to the Windowsx64 build/nightly, exactly prior to when bug 1362866 landed? I can test that (I really dont want to do a regression again. Using mozregression on this bug was painful)

I sure can. https://archive.mozilla.org/pub/firefox/tinderbox-builds/mozilla-central-win64/1495576949/firefox-55.0a1.en-US.win64.zip

I can reproduce this bug with the build of comment 17 (buildid: 20170523150229) So my mozregression range was bad :(

Bah! Mayank, I'm so sorry - two new pieces of information: 1) I can reproduce your issue 2) The build I gave you was the wrong one, and still had my patches in it Now that I've reproduced the issue, it does indeed look like the tab is still "blank", and that bug 1362866 is at fault. Sorry for the runaround, and thanks for reporting!

no problem :)

Comment on attachment 8871857 [details] Bug 1367964 - Skip async tab switching blank tab optimization when the window is minimized. https://reviewboard.mozilla.org/r/143362/#review147100

Pushed by mconley@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/c72b350230aa Skip async tab switching blank tab optimization when the window is minimized. r=billm

I have reproduce this issue using an old Nightly from 2017-05-25. This issue is verified fixed on 55.0b2 (20170615133456) under Windows 10 x64, Ubuntu 16.04 x64 LTS and Mac OS X 10.11.6.