Scrolling message in preview breaks rendering

[Michał Sawicz]

Very often my mail preview pane gets broken, scrolling the message renders it unusable. Only way to fix that is to restart Evolution.

Reading messages in separate windows is affected, too.

Please see screenshots.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: evolution 3.2.3-0ubuntu3
ProcVersionSignature: Ubuntu 3.2.0-18.29-generic 3.2.9
Uname: Linux 3.2.0-18-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 1.94.1-0ubuntu2
Architecture: amd64
Date: Mon Mar 19 14:04:23 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120226)
SourcePackage: evolution
UpgradeStatus: No upgrade log present (probably fresh install)

[Mathieu Trudel-Lapierre (cyphermox)]

I don't think that's evolution -- it works just fine on multiple systems I've tried. I'll guess wildly and say it's more likely to be X or compiz, so let's reassign this to compiz for starters.

Can you please confirm that this is indeed with compiz running, so perhaps in Unity? Or are you using gnome shell?

[Michał Sawicz (saviq)]

Nope, unity-2d here with metacity.

[Ken VanDine (ken-vandine)]

I see this as well and have confirmed it happens in unity 2d as well. The preview pane stops getting updates, so switching selected mail doesn't update the preview pane. For me it happens even without scrolling, but it seems to be most common on very long mails. I can easily reproduce it with launchpad merge proposal emails, so maybe the contents of a diff being rendered triggers something? Maybe a gtkhtml bug?

[Ken VanDine (ken-vandine)]

@saviq: can you try testing with disabling overlay scrollbars?

You can do that by running it from a terminal like this:
  LIBOVERLAY_SCROLLBAR=0 evolution

I haven't been able to reproduce it with them disabled, and can easily reproduce it with overlay scrollbars.

[Michał Sawicz (saviq)]

Hey, I actually can't reproduce any more at all.

My version of libgtkhtml-4.0-0 4.2.2-1ubuntu1.1 is from -proposed due to bug #961337, so maybe that fixes as a side-effect?

[Michał Sawicz (saviq)]

BTW, I have switched from nVidia to the Intel graphics in my Optimus setup, so it might be nvidia-related, can you comment?

[Ken VanDine (ken-vandine)]

I am on intel graphics. It has become harder to reliably reproduce this bug now, but I can still reproduce it. However, with overlay scrollbars disabled I have not been able to reproduce it. This is leading me to believe it is actually a overlay-scrollbar bug, I will run it exclusively with scrollbars for the rest of the day before I reassign the bug to that package.

[Nate Case (ncase-xes-inc)]

Same problem here. Fresh Ubuntu 12.04 install, and I get this problem about 5-6 times a day. Restarting Evolution is the only way to fix it each time (disabling and re-enabling message previews does not do the trick).

AMD/ATI graphics here, so it doesn't seem like nVidia vs. Intel vs. AMD/ATI make a difference.

I will try disabling overlay scrollbars to see if that makes a difference. It should only take a day for me to learn for sure since it happens so frequently.

[Nate Case (ncase-xes-inc)]

Update: I can confirm that disabling overlay scrollbars (via running with LIBOVERLAY_SCROLLBAR=0) made the problem disappear for me.

[Matt C (proteus400)]

This bug has been plaguing me for 6 months at least but I was unable to track it down - until today.

The preview pane hangs (won't refresh on scrolling, doesn't change emails and is generally unusable) as described.
This happens regularly to me and is always triggered by certain emails in my Inbox.

Usually the emails triggering this bug are plain-text (server/system-generated) multipart emails with, for example, long CSV attachments - or copy log files emailed to me from appliances. I have many emails that I cannot view. Evolution's preview window hangs 90% of the time on these emails. "Formatting Message" takes a long time on these messages too.

Force shutdown or restart of evolution is required to view any other email.

running with LIBOVERLAY_SCROLLBAR=0 makes the problem go away, albeit with a workaround.
Eureka!

As an Eclipse user too this LIBOVERLAY_SCROLLBAR has been a nuisance from day one of its inception. It bugs out all the main apps I use.

I suspect from visual observations that this issue is due to a rapid stream of continuous widget scroll area size change events that causes overlay scrollbar to break the widget. Some apps used to disappear; evolution has a widget hang.

[Dennis Baudys (thecondordb)]

I can definitively confirm this problem with the rendering problem of the message preview pane in evolution: No message preview content at all when selecting an email - or an old message is displayed or visual glitches like described above. Long multipart and HTML messages seem to trigger it in a reproducable way.

I'm using Ubuntu 12.04 64-Bit with kernel 3.2.0-32-generic # 51-Ubuntu SMP Wed Sep 26 21:33:09 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux and evolution 3.2.3-0ubuntu6. Unity (3D) with compiz and NVIDIA most recent drivers.

The workaround of starting evolution with
  LIBOVERLAY_SCROLLBAR=0 evolution
WORKS FINE for me, too!

So it really looks like the Unity overlay scrollbars are a BIG problem for evolution that should be fixed.

Thanks!

[Steve Graham (gram-steve)]

This is happening for me as well. On three different devices (all 12.04). Only happens on long messages.

These messages typically have been group discussions with multiple replies. The norm here is showing previous emails in the thread with "<" on each line of the previous thread. I got to thinking about this and the response I found from an Evolution developer saying this is related to gtkHTML.

I configured evolution (edit->preferences->mail preferences->html messages) to use Plain text mode by selecting the option to "Show suppressed HTML parts as attachments" and HTML Mode as "Only ever show plain text". Now I can't replicate the problem. HTML portions of inbound email are now attachments, which I can choose to view inline (handy because get a fair amount of email that is only html).

I think gtkHTML is getting blown away by what it thinks is an enormous amount of html open tags and no closing ones. But that is just a hunch, I did not try to verify it.

[Matt C (proteus400)]

I still have this problem with liboverlayscrollbars + Evolution in Ubuntu 12.04.

Overlay scrollbars makes Evolution virtually unusable - email view windows (preview window, also affects opening email in a full window).

Periodically I reinstall/upgrade Ubuntu or install evolution security updates and lose the LIBOVERLAY_SCROLLBAR=0 environment workaround and boy do I soon know about it.

Is anyone still debugging liboverlayscrollbar?.