Error stack

Geoffrey Sneddon gsneddon at
Sun Jun 10 16:12:24 PDT 2012

On 10/06/12 23:57, John Tamplin wrote:
> On Sun, Jun 10, 2012 at 9:56 AM, Geoffrey Sneddon<gsneddon at>wrote:
>> It's not just Firefox addons that will break: GWT's output relies upon the
>> exact format of Error.stack[1]. I know Google Wave depended upon this, and
>> I believe other Google applications do too.
> Note that GWT can supply different deferred-bound implementations for
> different browsers, though generally we do runtime detection rather than
> compile time if there are few differences between versions.  Of course,
> that would only affect deployed apps if they recompiled, but I wouldn't
> expect that would be much of a problem for any currently maintained apps.

Well, the Wave team only shipped Gecko/WebKit code, so you *had* to be 
compatible with either one of the compile-time branches if you wanted to 
have a browser that supported Wave. The fact it *can* support different 
implementations is only relevant if people ship the code. :)

To be fair, I've only seen a few things that have relied upon 
Error.stack (all through GWT and not shipping all the various 
compile-time options!) and I think they were all Google sites, so 
hopefully they'd all be updated, allowing convergence of Error.stack 

(Though it is perhaps saying about maintenance of that code that the 
Opera code-branch relies upon Futhark behaviour, which hasn't been 
shipped in desktop or mobile for over two years now, and the specific 
behaviour it relies on depends upon a non-standard pref setting that 
didn't even exist in mobile.)

Geoffrey Sneddon — Opera Software

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