647619 - Fire infinite errors "preview is undefined"

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[Aquila]

User-Agent:       Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0
Build Identifier: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0

I'm just coding some html/javascript page on my local web server and testing it in firefox with firebug but the native console is spammed with the following error:

Error: preview is undefined
Source File: resource://gre/modules/WindowsPreviewPerTab.jsm
Line: 380

Reproducible: Didn't try

Steps to Reproduce:
1. Some local pages? I don't know if is a problem with the localhost

Actual Results:  
The console is spammed with 100 time the same error, it is useless you can't find any error because it get filled all the time.

Expected Results:  
Good question, perhaps add a check if the "preview" is not null?

Comment 1

[(mostly gone) XtC4UaLL [:xtc4uall]]

Is your Issue reproducible without Extensions in Safe-Mode and/or using a new Profile?
https://support.mozilla.com/en-US/kb/Safe+Mode
https://support.mozilla.com/en-US/kb/Managing+profiles#Creating_a_profile

The Error would be available in the Error Console.

Comment 2

[[e-mail]]

I also am seeing this error.  For me, it happens from a Greasemonkey script that used to work just fine.  It started failing with my last FF update a few weeks ago.

The error is:
preview is undefined
resource://gre/modules/WindowsPreviewPerTab.jsm
Line 380

When my greasemonky script tries to open a URL in a tab, it gets this error first:

Index or size is negative or greater than the allowed amount"  code: "1
jar:file:///C:/Users/.../components/greasemonkey.js
Line 287

The script is pretty trivial, so I'll just include it here.  Since using this script saves me a LOT of time when reading comics, I'll probably just revert back to an older version of FF.

// ==UserScript==
// @name Belfry Tabs
// @description Open Belfry.Com Subscriptions in tabs
// @namespace http://john.casadelgato.com
// @version 1.0
// @include http://belfrycomics.net/misc/List
// ==/UserScript==

window.HeaderClickHandler = function( comic) {
        GM_log("HeaderClickHandler: " + comic);
        setTimeout( function() {GM_openInTab( comic);} ,0);
}

GM_log("Doc URL: " + document.URL);

var len = document.body.children[0].children.length;

GM_log("Num Children=" + len);

for (var idx = 0; (idx < document.body.children[0].children.length); idx++) {
        var child = document.body.children[0].children[idx];

        GM_log("child.localName = " + child.localName + ", child.className = " + child.className);


        if (("h3" == child.localName) && ("header" == child.className)) {
                GM_log( "matched!");
                var fcn = "";
                var c1 = document.body.children[0].children[idx + 1];

                for each (var curr in c1.children) {
                        GM_log( "curr: " + curr.textContent);

                        for each (var sub1 in curr.children) {
                                if (("" == sub1.className) && ("a" == sub1.localName)) {
                                        fcn += "HeaderClickHandler('" + sub1.href + "');"
                                }
                        }
                }

                GM_log( "fcn = " + fcn);
                child.addEventListener("click", new Function( fcn), false);
        }
}

Comment 3

[jphoenix]

I have been able to reproduce this symptom in conjunction with the add-on Last tab close button 0.3.4.

Open firefox 5.0 to a single empty tab & open Error Console.
Close the empty tab & the message appears once in the Error Console.
Click on the Error Console window title bar & 1 additional iteration of the message appears.
Click on the Firefox main window title bar & 1 additional iteration of the message appears.
Enter Private Browsing mode & clear the console.  No messages.
Close the Private Browsing entered tab.  The messages return.
Opening a new tab so there are two open before closing the first and no messages.

Conclusion: Last tab close button is one way to cause this message to appear.

Comment 4

[Wayne Mery (:wsmwk)]

Aquila, jphoneix, can you still reproduce when using a current version started in safe mode??

Comment 5

[jphoenix]

My ability to reproduce this bug ended with FF 6 or 7.  I was only ever able to reproduce on my work computer, never my home computer which had the same FF & LTC releases.  Known difference was work machine had Win 7-32, home had XP with latest fixpack.

Comment 6

[Phoenix]

Resolved per whiteboard and Comment 5