44147 - improperly parented modal dialog in caps

Status: VERIFIED FIXED

(Core :: Security: CAPS, defect, P3)

Description

[Dan M]

nsNetSupportDialog should only be used as a backup plan if no other nsIPrompt 
interface is available. It has been used in dozens of places because of its 
seductive convenience. But it's flawed, creating modal windows that don't behave 
correctly; the cause of various blanket bugs like 25684 and 39439 (both currently 
considered nsbeta2+).
  This problem can only be fixed by trying much harder to find a proper window to 
be the modal dialog's parent. nsNetSupportDialog should be relegated to providing 
backup when herculean efforts to locate the actual parent window fail for some 
reason.
  As an example, the cookie service has been taught to use a proper parent window 
for its dialog by laboriously storing a reference to that window's nsIPrompt in 
nsHTTPChannel, from which it can be extracted and passed around while processing 
notification events, punting to nsNetSupportDialog only when no other choice is 
available. That same sort of thing needs to be done in many more places.
  One such place is nsScriptSecurityManager.cpp, CheckConfirmDialog.
  Happy recipients of this bug would spread the happiness most widely if they 
would start using a good nsIPrompt window. The "modal windows don't behave 
nicely" bugs are being made dependent on this bug and its siblings, and will 
eventually be closed as "as fixed as they're going to get" once these have all 
been considered.

Comment 1

[Mitchell Stoltz (not reading bugmail)]

Reassigning to morse, who wrote CheckConfirmDialog (I think).

Comment 2

[Stephen P. Morse]

I may have written that dialog for my own module, but I have no idea of how it 
is used in your module.  The problem is not with the dialog but with finding a 
window for it and that is module-specific.  Reassigning back to mstoltz.

Comment 3

[Dan M]

  Yes -- it would be fairly easy to add a parameter to CheckConfirmDialog, giving 
it for its use an nsIPrompt that corresponds to the actual (browser) window 
involved. Steve could do that. The real issue is getting that nsIPrompt, which is 
more a problem of the module calling CheckConfirmDialog.

Comment 4

[Mitchell Stoltz (not reading bugmail)]

I'll look at this soon.

Comment 5

[Mitchell Stoltz (not reading bugmail)]

Maybe nsbeta3.

Comment 6

[Doug Turner (:dougt)]

Because of the use of nsCommonDialogs, or the use of the nsIPrompt service, this 
component can not be used for embedding.  Adding the embedding keyword.



How To Bring Up A Modal Dialog: 

You need to know what window you want to have modality against.  This will be a 
nsIDOMWindow.  Using a magic "hidden" window breaks modality and embedding 
application may not have this hack.  One you have the parent DOMWindow, you 
simply: 
  

nsCOMPtr<nsIPrompt> prompter; 
aDOMWinow->GetPrompt(getter_AddRefs(prompter)); 
if (prompter) 
    prompter-> 
  

Any other way that you try to bring up a dialog may not work in an embedding 
application. To reiterate, do not use the nsICommonDialogs interface -or- a
nsIPrompt service if you want your component in a non-seamonkey app. 
  

I don't have a DOMWindow?! 

If you don't have a DOMWindow, you need to get one.  Just about every place I 
saw that used the hidden window, could have used the real parent window with
some work.  There really is no place in the code where we should be displaying a 
modal dialog without knowing what parent window we are modal against.  If you 
find a case where you don't have a top level window, lets talk. 

Comment 7

[waqar]

adding myself to cc list

Comment 8

[Patrick C. Beard]

Upgrading to [nsbeta3+].

Comment 9

[Mitchell Stoltz (not reading bugmail)]

Fix checked in.

Comment 10

[Paul Wyskoczka]

Updating QA Contact to [e-mail]

Comment 11

[John Unruh]

Verified with the 9/22 Win98 build.