617323 - object freed right after usage

Status: RESOLVED INCOMPLETE

(Core :: JavaScript Engine, defect)

Description

[Petko D. (pdp) Petkov]

User-Agent:       Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_5; en-us) AppleWebKit/533.19.4 (KHTML, like Gecko) Version/5.0.3 Safari/533.19.4
Build Identifier: 1.9.2.10 - 1.9.2.12

A object is freed automatically right after it is used within the same function. The condition is only triggered while the code runs within a dom worker. The reason for this behaviour is unknown.

Reproducible: Sometimes

Steps to Reproduce:
The code is part of a custom xulrunner app which should be ported to a Firefox extension.
Actual Results:  
The object is freed before is used.

Expected Results:  
This shouldn't happen in theory.

Here is an example:

var fuzzRequest = this.currentFuzzEntry.request; 
// TODO: remove this try/catch wrapper 
try { 
   self.scheduler.schedule(fuzzRequest.method, fuzzRequest.url,fuzzRequest.protocol, fuzzRequest.headers, fuzzRequest.data, this); 
} catch (e) { 
   dump('[x] ' + JSON.stringify(fuzzRequest) + '\n'); 
   dump('[x] ' + JSON.stringify(this.currentFuzzEntry.request) + '\n'); 
   dump('[x] ' + JSON.stringify(this.currentFuzzEntry) + '\n'); 
   debug.printCallStack('[x] '); 
}

In theory fuzzRequest should contain the value of this.currentFuzzEntry.request. However, while this.currentFuzzEntry.request is not equal to null (i.e. contains an object), fuzzRequest is null and the above code fails. This is the reason why it is wrapped in a try/catch statement.

It is unknown at this stage why this happens. It will be very helpful if somebody can let me know what is going on here.

Comment 1

[Blake Kaplan (:mrbkap) (inactive)]

Petko, have you had any luck tracking this down?

Comment 2

[Wayne Mery (:wsmwk)]

(In reply to Blake Kaplan (:mrbkap) (please use needinfo!) from comment #1)
> Petko, have you had any luck tracking this down?

Comment 3

[Firefox Bug Husbandry Bot]

2019-03-06

This bug is part of a group of bugs which have had an open needinfo for at least 12 weeks.

The request for information has not been answered, and we can't move forward on the bug so we are closing it.

If the defect is still present, please reopen this bug with an updated report.