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Problems with Exceptions (was Re: Bizarre problem with canvas) (Real Studio network user group Mailinglist archive)

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Problems with Exceptions (was Re: Bizarre problem with canvas)   -   Mike D.
  Re: Problems with Exceptions (was Re: Bizarre problem with canvas)   -   Dominik Fusina - The Captain
  Re: Problems with Exceptions (was Re: Bizarre problem with canvas)   -   Frank Bitterlich

Problems with Exceptions (was Re: Bizarre problem with canvas)
Date: 30.07.02 19:35 (Tue, 30 Jul 2002 11:35:21 -0700)
From: Mike D.
>Subject: Re: Bizarre problem with canvas
>From: "Steve Thomas" <<email address removed>>
>Date: Tue, 30 Jul 2002 10:30:04 +0100
>
>[...]
>The problem was that there was actually an unhandled exception in the
>constructor of the property that the canvas contained. So in the open event,
>the canvas tried to initialise the property, failed and opened up the
>debugger. I think this must have been firing the paint event of the canvas,
>which then tried to access the property to draw it. This threw up a second
>exception. Rather than displaying the original error, the debugger then
>jumped to this second error, giving the impression that the open event had
>never been run.
>
>This is quite a subtle problem, because I had assumed that once an error is
>hit, ALL code execution stopped. However, this is clearly not the case for
>the paint event. I should probably RealBug this as it confused the hell out
>of me!
>
>[...]
>Regards,
>Steve Thomas

I've found another problem where exceptions don't work. In OS X, if
you have an exception inside a window.showModal call, the exception
handler won't catch it until it pops up outside of the showModal call
(i.e. you can never get the IDE to open on the line of the exception
itself, instead it stops at the showmodal call).

I've also had lots of crashes with exceptions inside of running
threads, although I admit I've not tested this much with 4.5.

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Re: Problems with Exceptions (was Re: Bizarre problem with canvas)
Date: 31.07.02 07:07 (Wed, 31 Jul 2002 08:07:42 +0200)
From: Dominik Fusina - The Captain
on 30/07/02 20:35, Mike D. at <email address removed> wrote:

> I've also had lots of crashes with exceptions inside of running
> threads, although I admit I've not tested this much with 4.5.

Me too...

An old project which works fine on OSX / 4.0.2 crashes now under MACOS X /
4.5 (Build app). The crash is at the beginning (the app doesn't want to
start)... Gasp!

'Threads' is a very interesting track. I investigate in this direction.
Thanx.

Dominik Fusina
Captain of NEMO


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Re: Problems with Exceptions (was Re: Bizarre problem with canvas)
Date: 31.07.02 11:02 (Wed, 31 Jul 2002 12:02:49 +0200)
From: Frank Bitterlich
In OS 9, it's even more bizarre: Having an unhandled exception in a
modal-running window will be caught by the IDE, but afterwards, your app
is somehow half-running: You can't Run it again or Kill it, but you
can't quit the IDE or open another project, either. Time for a
three-finger salute ;)

Cheers,
Frank+++

"Mike D." wrote:
> I've found another problem where exceptions don't work. In OS X, if
> you have an exception inside a window.showModal call, the exception
> handler won't catch it until it pops up outside of the showModal call
> (i.e. you can never get the IDE to open on the line of the exception
> itself, instead it stops at the showmodal call).