Works for me.

I pressed printscrn to start ksnapshot, changed the Capture mode to
Window under cursor, clicked Take new snapshot, then clicked on the
window to get a snapshot of.

CC: (none) => davidwhodgins

Here I fix my description and bug title.

After a clean install of release iso and a clean KDE environment (without any old .kde4 folder), I still got a strange result.  

I launched a firefox window and use ksnapshot to grab window only, but the snapshot it gave me is a clean desktop without any window on it.  The result seems to always be the last photo it captures successfully.  Only capturing the whole screen without any delay would work everytime.  Other settings would not capture a new photo, just leave the last one.

Summary: ksnapshot would always grab the whole screen, no matter set to grab window under cursor only or rectangle area only => ksnapshot would only work when captureing the whole screen without delay. Other settings would not work.

I'm not able to reproduce here with the xguest user

Just in case are you sure you're not clicking a little to fast on knspashot?
Just after the first click when you select the « window » under the cursor, you should have a small aray to select the windows, if you click on the desktop it's going to take the full desktop, but clicking on the firefox allow to get only the firefox window ?

CC: (none) => balcaen.john

(In reply to comment #3)
> I'm not able to reproduce here with the xguest user
> 
> Just in case are you sure you're not clicking a little to fast on knspashot?

I'm not clicking too fast.

> Just after the first click when you select the « window » under the cursor, you
> should have a small aray to select the windows, if you click on the desktop
> it's going to take the full desktop, but clicking on the firefox allow to get
> only the firefox window ?

I have a small cross to ask me to select the window.  However, when I click any window I always got the same photo.  Even if I move the window to another position and click it, I still got the same photo before moving.

If you have any desktop effects try disabling them.

(In reply to comment #5)
> If you have any desktop effects try disabling them.

Yes!  Disabling my desktop effects would make this problem gone.

Would anyone please take a look at that?

I'm not able to reproduce here (it's working with desktop effect enable).
Just a try, you're not using eventually a nvidia card ?

(In reply to comment #7)
> I'm not able to reproduce here (it's working with desktop effect enable).
> Just a try, you're not using eventually a nvidia card ?

No.  My laptop and desktop PC in the office are using internal Intel card (driver i915).

The KWin desktop effect "Screenshot" seems to be the problem here.
After disabling it, ksnapshot worked again as expected.

CC: (none) => c_lohmann

(In reply to comment #9)
> The KWin desktop effect "Screenshot" seems to be the problem here.
> After disabling it, ksnapshot worked again as expected.

It's working here with this functionnality enable :/

@ Franklin 
Does this workaround fix the problem for you ?

(In reply to comment #10)
> (In reply to comment #9)
> > The KWin desktop effect "Screenshot" seems to be the problem here.
> > After disabling it, ksnapshot worked again as expected.
> 
> It's working here with this functionnality enable :/
> 
> @ Franklin 
> Does this workaround fix the problem for you ?

Are you using Intel graphics? It seems to occur on Intel cards. At least did for me. I haven't tested but if "Screenshot" effect is enabled by default then it should be disabled by default.

CC: (none) => sander.lepik

(In reply to comment #10)
> (In reply to comment #9)
> > The KWin desktop effect "Screenshot" seems to be the problem here.
> > After disabling it, ksnapshot worked again as expected.
> 
> It's working here with this functionnality enable :/
> 
> @ Franklin 
> Does this workaround fix the problem for you ?

Yes.  This workaround fixes the problem for me.

(In reply to comment #11)
> Are you using Intel graphics? It seems to occur on Intel cards. At least did
> for me. I haven't tested but if "Screenshot" effect is enabled by default then
> it should be disabled by default.

Yes.  I'm using Intel (internal) graphic card with driver i915.

Maybe file a bug report upstream, having the Screenshot effect shouldn't break ksnapshot functionality.

(In reply to comment #13)
> > @ Franklin 
.
Did y

(In reply to comment #13)
> > @ Franklin 
Did you report upstream as suggested by ahmad ?

(In reply to comment #15)
> (In reply to comment #13)
> > > @ Franklin 
> Did you report upstream as suggested by ahmad ?

Sorry, I missed the message.

I just filed a bug in KDE:

https://bugs.kde.org/show_bug.cgi?id=277416

Ok.
Just one more thing: you're on Mageia 1 currently or still Cauldron?

Keywords: (none) => UPSTREAM
See Also: (none) => https://bugs.kde.org/show_bug.cgi?id=277416

(In reply to comment #17)
> Ok.
> Just one more thing: you're on Mageia 1 currently or still Cauldron?

Mageia 1.

nothing happened upstream

assigning to maintainer for him to decide what to do with this bug report

CC: (none) => marja11
Assignee: bugsquad => balcaen.john

Well, we've got this situation :
-> the bug is an upstream bug (in kde or eventually in intel graphic driver )
-> i'm not able to reproduce on my netbook (but using an intel i810 card)
-> there's an easy workaround


So we should :
- let the bug report open (just in case it's ever fixed upstream)
- add this bug report in errata with the workaround.

Weird, it has the "unconfirmed" status upstream, yet there were already two duplicates :/

from kde.org

"I had this problem in connection with the KWin desktop effect "Screenshot" (it was enabled by default). After disabling the effect, ksnapshot worked again as expected."

(and seems resolved in kde 4.8.1 )

are you still using mageia 1 or now mageia 2 ?

CC: (none) => nicolas.lecureuil

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Status: NEW => RESOLVED
Resolution: (none) => WONTFIX