Desktop login to unity leads to hang and compiz crash when X Server Display Confirmation is clicked on

[Note: Patch 06 was introduced to fix bug #604525]

Hmm, from a casual skim through the patch I don't see an obvious part of the patch which could cause this particular problem, but it's a moderately long patch, and perhaps has a loose pointer or something.

Doug, since you can reproduce the issue and seem comfortable patching/building the source, would you be willing to help narrow down where in the patch the wayward code line is? Try commenting out different lines in the source code that the patch changed to identify what triggers the behavior.

Subbing upstream NVIDIA project as well, since on bug #604525 Aaron indicated they'd be considering the patch for inclusion upstream as well, and should be aware of this potential regression issue.

A bit of a change -
Thru a fully updated natty as of 6:30 pm (east coast usa), it now works in a Classic login to gnome-panel/compiz enabled

On the other hand a Desktop login to unity - when trying to click on the X Server Display Confirmation menu it hangs and then crashes both nvidia-settings and most likely compiz (window decorations disappear, ect.

(it may be possible (?) that this current compiz/unity bug has creates issues beyond the obvious.
https://bugs.launchpad.net/ubuntu/+source/compiz/+bug/690461
(wish I could figure out the deal with those nice little blue links
Am attaching .xsession-errors (old) from crash

I think I'll try a fresh, updated iso and install, see if it's any different

Finally - unless I'm missing something blatantly obvious or somewhat obscure I see absolutely no difference between a patched and unpatched nvidia-settings

With a fresh install of iso available today on a laptop, (dell 1330, nvidia 8400m GS), basically same the same thing -
Desktop login to unity, crashed window dec., then nvidia-settings
Classic login to gnome-panel, initially just froze up on the X Server Display Confirmation menu, after applying the small set of updates ( mainly gnome-panel and indicator package updates), it works fine

Returning to Desktop login still the same crashes.

Employing the second way to run unity - login to Classic with the unity plugin enabled - it works fine
So the Classic login is good with either the unity or gnome-panel interface
The Desktop login is a no go.

(- this is not the only instance where a Classic > unity login is better behaved than a Desktop > unity login.
I think I've restarted, logged in/out more in the last couple of weeks than in the last couple of years altogether...

Thanks for all the testing Doug!

So if I read your comments correctly, you've ruled out the 06 patch as a culprit? I.e. you can reproduce the crash with or without it?

It sounds like you find the bug occurs only a proportion of the time (which might explain why it at first seemed correlated to the patch)?

At this point it sounds like the unity initialization process is misbehaving when the nvidia driver is present. I'll update the title.

Btw thanks for testing a fresh iso reinstall, that eliminates a host of -nvidia driver upgrade-related GLX misbehaviors.

I don't seem to be able to reproduce this, although I've not tested the very latest code.

I've successfully used the dropdown menu in a Unity session on my nvidia laptop. I'll update the laptop and give it another go.

One of the difficulties here is that
one - there are some inconsistencies when using the same login, it not always the same, though if needed a logout/in or 2 can stabilise and give a clean login

two - there is clearly something different between the Desktop and Classic logins to unity. At this point I'd think any updates/patches/tests need to be run on Desktop > unity to test them, probably more than once (the 2 last updates to compiz highlight that
https://bugs.launchpad.net/ubuntu/+source/compiz/+bug/691561

three - when switching logins there is a good possibility of having the compizconfig settings for that profile unset, which then leads to having to re-enable to match their respective defaults. (if that matters ?

four - making some changes to compizconfig will crash compiz - it may take a restart and or a couple of logout/ins to return a clean load of that respective interface/profile

So - booting to a clean load of Classic > gnome-panel nvidia-settings works fine BUT it's not guaranteed to work 100% of the time, the same can be said for the Classic > unity login. If it fails (rare), it does so in same manner as the Desktop > unity. The difference is a logout/in will always fix in the former 2, nothing fixes Desktop > unity (except below

The one constant here seems to be the failure of the window decorator plugin, so -

Booting to a clean load of Desktop > unity with the window decorator plugin previously disabled, then nvidia-settings works fine

Just finally - While can demonstrate here identically of 2 different but not uncommon hardwares, this definitely begs further confirmation.
If valid, based on the progression so far as seen here, there doesn't seem any reason to take action, maybe better to wait for next set of compiz update(s)
(unless something is apparent, maybe in relationship to the window dec.

So, I've built nvidia-settings with the 06 patch removed, and it doesn't break in this way. It looks like the patch is to blame, and we should therefore remove it until we've worked out what's going wrong.

Just to note - you can, if using a certain 'method', successfully open X Server
 Display Confirmation while using the Desktop > unity login. (though clearly that's not the intention
Also that it doesn't immediately crash compiz - actually takes several seconds during which the crash can be averted.

This bug was fixed in the package nvidia-settings - 260.19.21-0ubuntu3

---------------
nvidia-settings (260.19.21-0ubuntu3) natty; urgency=low

  * Drop patch debian/patches/06_layout_drop_down.patch: Causes regression
    when used with unity.
    (Closes LP: #692677, reopens #604525)
 -- Bryce Harrington <email address hidden> Mon, 03 Jan 2011 13:08:19 -0800

As per comment #12 I've dropped the patch for now, and re-opened the original bug report.

Since it sounds like upstream is in process of taking the patch, I guess there is a potential for the bug to return, so continued efforts to troubleshoot this patch would not be in vain.

Just to follow up -
at least here inc. the 06 patch in nvidia-settings no longer causes any issues on any interface.
While I didn't ck. previously it's likely bug fixes to compiz ... +glibmainloop4-0ubuntu4 squared this up. (for the moment at least

That version is no more supported; please open a new bug report if the actual archive found version also has the same issue.