574941 - Errors within events triggered by .dispatchEvent are not shown in the Error Console

Status: RESOLVED DUPLICATE of bug 503244

(Core :: XPConnect, defect)

Description

[jorisvdwel]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.4) Gecko/20100611 Firefox/3.6.4
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.4) Gecko/20100611 Firefox/3.6.4

When an event is triggered by Node.dispatchEvent, any errors within that event are not shown in the Error Console or in firebug. They do however, show up in venkman (if I recall correctly venkman shows exceptions even if they are caught by try... catch).

Reproducible: Always

Steps to Reproduce:
1. Open the attached test case
2. Open the Error Console
3. Press "Trigger Error"
4. Press "Trigger Error (dispatchEvent)"
Actual Results:  
3. An alert is displayed AND an error is shown in the error console
4. An alert is displayed, but no error in the error console

Expected Results:  
4. Should display an alert AND an error in the error console

Comment 1

[jorisvdwel]

Attachment: Test Case

Comment 2

[Boris Zbarsky [:bzbarsky]]

Sounds like the usual XPConnect eating the exception when calling into a JS-implemented component (nsIDOMEventListener in this case) with JS on the stack....

Comment 3

[Mihai Sucan [:msucan]]

Just bumped into this issue yesterday. It still affects Firefox 4 nightly builds. I tested with Ubuntu Linux 64 bits, so I presume this issue is cross-platform.

Comment 4

[Nochum Sossonko [:Natch]]

Confirming per comment 3.

Comment 5

[Tyler Breisacher]

I don't know if this is important, but this is true for "throw"s as well as errors. Replace both "obj.bla.def = 5;" lines with "throw new Error('this is an error')" and the bug still occurs.

Comment 6

[Myers Carpenter]

This is a duplicate of #503244