Closed Bug 1264402 Opened 7 years ago Closed 7 years ago

[e10s] Dragging tab from one window to another on different displays doesn't always load


(Firefox :: Tabbed Browser, defect, P4)

48 Branch



Tracking Status
e10s + ---
firefox48 --- affected


(Reporter: mcote, Unassigned)



This behaviour started in Nightly for me a few days ago.  When I drag a tab from the window on my built-in (MBP Retina) display to a window in an external monitor, I get the loading icon forever.  This does not happen (i.e. it works fine) if I drag from the same windows if they are both on the same display.  It also appears to work fine if I drag a tab from the built-in display to the external monitor as a new window.  Interestingly, dragging more tabs to that same new window works, but it continues to not work on my old window.
Spoke to mcote - what he's referring to by "loading icon" is the async tab switch spinner.
tracking-e10s: --- → ?
Actually, it seems that dragging a tab from one window to another even on the same display doesn't usually work.
Would you mind pasting your about:support?
Flags: needinfo?(mcote)
Application Basics

Name: Firefox
Version: 48.0a1
Build ID: 20160413030239
Update Channel: nightly
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:48.0) Gecko/20100101 Firefox/48.0
OS: Darwin 15.4.0 x86-64
Multiprocess Windows: 3/3 (Enabled by user)
Safe Mode: false

Crash Reports for the Last 3 Days

All Crash Reports (including 2 pending crashes in the given time range)


Name: Firefox Hello
Version: 1.2.6
Enabled: true

Name: Multi-process staged rollout
Version: 1.0
Enabled: true

Name: Pocket
Version: 1.0
Enabled: true

Name: Abduction!
Enabled: false
ID: {b0e1b4a6-2c6f-4e99-94f2-8e625d7ae255}

Name: About sessionstore
Version: 0.32.1-signed
Enabled: false
ID: aboutsessionstore@dt

Name: Adblock Plus
Version: 2.7.2
Enabled: false
ID: {d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d}

Name: Drumpfinator
Version: 0.9.5
Enabled: false

Name: feedly
Version: 16.0.528.1-signed
Enabled: false
ID: feedly@devhd

Name: Firefox Interest Dashboard
Enabled: false
ID: firefox.interest.dashboard@up.mozilla

Name: Force-TLS
Enabled: false
ID: forcetls@sid.stamm

Name: gtranslate
Version: 0.13.0
Enabled: false
ID: {aff87fa2-a58e-4edd-b852-0a20203c1e17}

Name: LastPass
Version: 3.3.1
Enabled: false

Name: Lazarus: Form Recovery
Version: 2.3.1-signed
Enabled: false

Name: LinkChecker
Enabled: false
ID: {49f3fc85-dcfe-4e42-9301-226ebe658509}

Name: Mass Password Reset
Version: 1.05.1-signed
Enabled: false
ID: masspasswordreset@johnathan.nightingale

Name: Media Hint
Enabled: false
ID: mediahint@jetpack

Name: SQLite Manager
Enabled: false

Name: uniqtabs (Unique Tabs)
Version: 0.30.0
Enabled: false

Name: Whimsy Pro
Version: 1.0.8
Enabled: false
ID: jid1-6mUPixNFCjAgkg@jetpack


Asynchronous Pan/Zoom: wheel input enabled
Device ID: 0x162b
GPU Accelerated Windows: 3/3 OpenGL (OMTC)
Supports Hardware H264 Decoding: Yes
Vendor ID: 0x8086
WebGL Renderer: Intel Inc. -- Intel(R) Iris(TM) Graphics 6100
windowLayerManagerRemote: true
AzureCanvasAccelerated: 1
AzureCanvasBackend: skia
AzureContentBackend: skia
AzureFallbackCanvasBackend: none

Important Modified Preferences

accessibility.typeaheadfind.flashBar: 0
browser.cache.disk.capacity: 358400
browser.cache.disk.filesystem_reported: 1
browser.cache.disk.hashstats_reported: 1
browser.cache.disk.smart_size.first_run: false
browser.cache.disk.smart_size.use_old_max: false
browser.cache.frecency_experiment: 1 true
browser.places.smartBookmarksVersion: 7
browser.sessionstore.upgradeBackup.latestBuildID: 20160413030239
browser.startup.homepage: chrome://ubufox/locale/
browser.startup.homepage_override.buildID: 20160413030239
browser.startup.homepage_override.mstone: 48.0a1
browser.tabs.crashReporting.emailMe: true
browser.tabs.crashReporting.includeURL: true
browser.tabs.remote.autostart: true
browser.tabs.warnOnClose: false
browser.urlbar.userMadeSearchSuggestionsChoice: true
dom.apps.reset-permissions: true
dom.mozApps.used: true
dom.push.userAgentID: 1a6a71eea2574ff3be78d60344072064
extensions.lastAppVersion: 48.0a1
font.internaluseonly.changed: true
gfx.blacklist.direct2d: 3
gfx.crash-guard.glcontext.appVersion: 44.0.2
gfx.crash-guard.glcontext.deviceID: 0x162b
gfx.crash-guard.status.glcontext: 2
media.benchmark.vp9.fps: 536
media.gmp-gmpopenh264.abi: x86_64-gcc3-u-i386-x86_64
media.gmp-gmpopenh264.lastUpdate: 1450746198
media.gmp-gmpopenh264.version: 1.5.3
media.gmp-manager.buildID: 20160413030239
media.gmp-manager.lastCheck: 1460552485
media.webrtc.debug.aec_log_dir: /tmp/
media.webrtc.debug.log_file: /tmp/WebRTC.log
network.cookie.cookieBehavior: 3
network.cookie.prefsMigrated: true
network.predictor.cleaned-up: true
places.database.lastMaintenance: 1459975721
places.history.expiration.transient_current_max_pages: 104858
plugin.disable_full_page_plugin_for_types: application/pdf
plugin.importedState: true
plugin.state.flash: 1
print.print_bgcolor: false
print.print_bgimages: false
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print.print_duplex: 1515870810
print.print_evenpages: true
print.print_in_color: true
print.print_margin_bottom: 0.5
print.print_margin_left: 0.5
print.print_margin_right: 0.5
print.print_margin_top: 0.5
print.print_oddpages: true
print.print_orientation: 0
print.print_page_delay: 50
print.print_paper_data: 0
print.print_paper_height: 11.00
print.print_paper_size_type: 1
print.print_paper_size_unit: 0
print.print_paper_width: 8.50
print.print_resolution: 1515870810
print.print_reversed: false
print.print_scaling: 1.00
print.print_shrink_to_fit: true
print.print_to_file: false
print.print_unwriteable_margin_bottom: 56
print.print_unwriteable_margin_left: 25
print.print_unwriteable_margin_right: 25
print.print_unwriteable_margin_top: 25
print.printer_MTV2-Raiders.print_bgcolor: false
print.printer_MTV2-Raiders.print_bgimages: false
print.printer_MTV2-Raiders.print_duplex: 1515870810
print.printer_MTV2-Raiders.print_edge_bottom: 0
print.printer_MTV2-Raiders.print_edge_left: 0
print.printer_MTV2-Raiders.print_edge_right: 0
print.printer_MTV2-Raiders.print_edge_top: 0
print.printer_MTV2-Raiders.print_evenpages: true
print.printer_MTV2-Raiders.print_in_color: true
print.printer_MTV2-Raiders.print_margin_bottom: 0.5
print.printer_MTV2-Raiders.print_margin_left: 0.5
print.printer_MTV2-Raiders.print_margin_right: 0.5
print.printer_MTV2-Raiders.print_margin_top: 0.5
print.printer_MTV2-Raiders.print_oddpages: true
print.printer_MTV2-Raiders.print_orientation: 0
print.printer_MTV2-Raiders.print_page_delay: 50
print.printer_MTV2-Raiders.print_paper_data: 0
print.printer_MTV2-Raiders.print_paper_height: 11.00
print.printer_MTV2-Raiders.print_paper_size_type: 1
print.printer_MTV2-Raiders.print_paper_size_unit: 0
print.printer_MTV2-Raiders.print_paper_width: 8.50
print.printer_MTV2-Raiders.print_resolution: 1515870810
print.printer_MTV2-Raiders.print_reversed: false
print.printer_MTV2-Raiders.print_scaling: 1.00
print.printer_MTV2-Raiders.print_shrink_to_fit: true
print.printer_MTV2-Raiders.print_to_file: false
print.printer_MTV2-Raiders.print_unwriteable_margin_bottom: 21
print.printer_MTV2-Raiders.print_unwriteable_margin_left: 15
print.printer_MTV2-Raiders.print_unwriteable_margin_right: 15
print.printer_MTV2-Raiders.print_unwriteable_margin_top: 21
print.printer_Samsung-ML-1740_w500.print_bgcolor: false
print.printer_Samsung-ML-1740_w500.print_bgimages: false
print.printer_Samsung-ML-1740_w500.print_duplex: 1515870810
print.printer_Samsung-ML-1740_w500.print_edge_bottom: 0
print.printer_Samsung-ML-1740_w500.print_edge_left: 0
print.printer_Samsung-ML-1740_w500.print_edge_right: 0
print.printer_Samsung-ML-1740_w500.print_edge_top: 0
print.printer_Samsung-ML-1740_w500.print_evenpages: true
print.printer_Samsung-ML-1740_w500.print_in_color: true
print.printer_Samsung-ML-1740_w500.print_margin_bottom: 0.5
print.printer_Samsung-ML-1740_w500.print_margin_left: 0.5
print.printer_Samsung-ML-1740_w500.print_margin_right: 0.5
print.printer_Samsung-ML-1740_w500.print_margin_top: 0.5
print.printer_Samsung-ML-1740_w500.print_oddpages: true
print.printer_Samsung-ML-1740_w500.print_orientation: 0
print.printer_Samsung-ML-1740_w500.print_page_delay: 50
print.printer_Samsung-ML-1740_w500.print_paper_data: 0
print.printer_Samsung-ML-1740_w500.print_paper_height: 11.00
print.printer_Samsung-ML-1740_w500.print_paper_size_type: 1
print.printer_Samsung-ML-1740_w500.print_paper_size_unit: 0
print.printer_Samsung-ML-1740_w500.print_paper_width: 8.50
print.printer_Samsung-ML-1740_w500.print_resolution: 1515870810
print.printer_Samsung-ML-1740_w500.print_reversed: false
print.printer_Samsung-ML-1740_w500.print_scaling: 1.00
print.printer_Samsung-ML-1740_w500.print_shrink_to_fit: true
print.printer_Samsung-ML-1740_w500.print_to_file: false
print.printer_Samsung-ML-1740_w500.print_unwriteable_margin_bottom: 21
print.printer_Samsung-ML-1740_w500.print_unwriteable_margin_left: 15
print.printer_Samsung-ML-1740_w500.print_unwriteable_margin_right: 15
print.printer_Samsung-ML-1740_w500.print_unwriteable_margin_top: 21
privacy.donottrackheader.enabled: true
privacy.sanitize.migrateClearSavedPwdsOnExit: true
privacy.sanitize.migrateFx3Prefs: true
privacy.trackingprotection.enabled: true
privacy.trackingprotection.introCount: 20
security.disable_button.openCertManager: false
security.sandbox.content.tempDirSuffix: {f0dbda5a-66e0-4a40-83f8-4e99afcc14ec}
services.sync.declinedEngines: adblockplus,prefs,addons
services.sync.engine.addons: false
services.sync.engine.prefs: false
services.sync.engine.prefs.modified: false
services.sync.lastPing: 1460558914
services.sync.lastSync: Wed Apr 13 2016 15:57:32 GMT-0400 (EDT)
services.sync.numClients: 4
storage.vacuum.last.index: 1
storage.vacuum.last.places.sqlite: 1458230661

Important Locked Preferences


Incremental GC: true


Activated: false
Prevent Accessibility: 0

Library Versions

Expected minimum version: 4.12
Version in use: 4.12

Expected minimum version: 3.24 Basic ECC Beta
Version in use: 3.24 Basic ECC Beta

Expected minimum version: 3.24 Basic ECC Beta
Version in use: 3.24 Basic ECC Beta

Expected minimum version: 3.24 Basic ECC Beta
Version in use: 3.24 Basic ECC Beta

Expected minimum version: 3.24 Beta
Version in use: 3.24 Beta

Experimental Features

Name: DisplayPort Size Tuning
Description: Measuring the effect of different displayport sizes on checkerboarding.
Active: false
End Date: 1457714777027
Branch: control
Flags: needinfo?(mcote)
Any chance you can use mozregression to find out what broke this? Something like:

./mach mozregression --good 2016-04-08 --profile path/to/your/regular/nightly/profile

should take < 5 minutes to narrow down, and would help a lot, especially if this is related to your profile at all.
Flags: needinfo?(mcote)
Summary: Dragging tab from one window to another on different displays doesn't always load → [e10s] Dragging tab from one window to another on different displays doesn't always load
Took a bit longer than five minutes :) but mozregression identified the offender as being bug 1254865.  This assumes everything was reliably reproducing.  I did notice that sometimes it would take an extra drag (back to the built-in screen) to exhibit the problem, so I made sure to do multiple drags on the good builds.

Hope this helps.
Flags: needinfo?(mcote)
Thanks for the work, mcote. We'll have this triaged tomorrow.
Depends on: 1254865
This works for me on Mac 10.12, Nightly 48.0a1, 20160419030312.  The Unique Tabs add-on looked like a suspect.  But I installed it and still could not reproduce this bug. 

mcote, when you have a chance, please try in a clean profile.
Flags: needinfo?(mcote)
Hm yeah, works fine with a new profile.

I just removed a bunch of add-ons from my main profile, including Unique Tabs, and, although they were all disabled, the problem seems to have gone away!
Flags: needinfo?(mcote)
Mark, can you keep an eye on this and renom if you run into again. We're guessing this is caused by the tabs addons, but we're not 100% sure. For now we're not going to block on this.
Blocks: e10s-addons
Priority: -- → P4
I spoke too soon.  The problem just manifested again (with my original profile and a bunch of add-ons removed).
Is it possible for someone from the QA team to try to reproduce Mark's bug here? I'm having no luck.
Keywords: qawanted
Hi Mark,

I have tested your issue on latest FF release (45.0.2) and latest Nightly build and could not reproduce it. I have dragged and dropped a tab from one window to another(located on a secondary monitor) and I didn't have any loading issues. I've tested this on a Mac Book Pro Retina with OS X 10.12.2 installed. I wasn't able to reproduce this regardless if I've dragged the tab from the retina display on the secondary monitor, nor if I've dragged the tab from the second monitor to the retina display.

Is this still reproducible on your end ? If yes, can you please retest this using latest FF release and latest Nightly build ( and report back the results ? When doing this, please use a new clean Firefox profile, maybe even safe mode, to eliminate custom settings as a possible cause (

Flags: needinfo?(mcote)
Keywords: qawanted
Hi, as I mentioned in comment 9, this does not happen with a clean profile.  It is still reproducible with my current profile on today's Nightly.  It was not reproducible in release.
Flags: needinfo?(mcote)
Although all my add-ons were disabled, I just removed them all and restarted.  So far the problem hasn't reproduced, but as I found before, sometimes it just takes a while.  I'll comment if I see it again.
Aaand just reproduced it.
Hi Mark,

Since this issue is not reproducible on a new profile, it seems to be related to custom settings you made on your profile. Is it safe to close this bug as RESOLVED WFM?

Flags: needinfo?(mcote)
See bug 1267844, where it looks like we have a reproducible test case.  Up to you if you want to resolve that one or this one.
Flags: needinfo?(mcote)
Thanks mcote!
Closed: 7 years ago
Resolution: --- → DUPLICATE
No longer depends on: 1254865
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