44163 - improperly parented modal dialog in nsImapIncomingServer.cpp

Status: VERIFIED FIXED

(MailNews Core :: Networking: IMAP, 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.
  There are two such places in nsImapIncomingServer.cpp: FEAlert and 
FEAlertFromServer.
  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

[Scott MacGregor]

I believe these bugs are supposed to be nsbeta2. See 44164 for an example.

Comment 2

[Jay Patel [:jay]]

Putting on [nsbeta2+] radar for beta2 fix. 

Comment 3

[Scott MacGregor]

setting estimated completion date.

Comment 4

[Scott MacGregor]

.

Comment 5

[Scott MacGregor]

I would not hold nsbeta2 for this. Per the leads meeting today that's the new
litmus test. Adding the nsbeta2-. 

Comment 6

[lchiang]

+ per mail triage

Comment 7

[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 8

[Scott MacGregor]

Attachment: proposed fix

Comment 9

[Scott MacGregor]

I've attached the fix for this. Bienvenu can you code review it? I just changed 
FEAlert and FEAlertFromServer to take a message window. Then instead of using 
the prompt service we get the prompt associated with the message window.

(most of the changes in nsImapIncomingServer are just white space)

Comment 10

[David :Bienvenu]

sure, r=bienvenu

Comment 11

[Scott MacGregor]

Fix checked in. 

Comment 12

[lchiang]

What is the dialog that gets brought up for this?  (so we can verify)

Comment 13

[Navin Gupta]

verifying ....

Comment 14

[Navin Gupta]

nsIPrompt is being used now.