Comments on: Exceptional Exception Handling Behavior http://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/ inquisitive: adjective. given to inquiry, research, or asking questions; eager for knowledge; intellectually curious Sun, 20 May 2012 21:55:00 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: Peterhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3691 Peter Fri, 17 Oct 2008 05:42:31 +0000 http://davybrion.com/blog/?p=501#comment-3691 I recommend that everybody that confirmed in the comments that they could repro, confirm this on the connect site as well. I recommend that everybody that confirmed in the comments that they could repro, confirm this on the connect site as well.

]]> By: Davy Brionhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3620 Davy Brion Wed, 15 Oct 2008 13:38:16 +0000 http://davybrion.com/blog/?p=501#comment-3620 I've heard from someone at MS that this bug is only present on X86too bad they don't update connect... I’ve heard from someone at MS that this bug is only present on X86

too bad they don’t update connect…

]]> By: Davy Brionhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3494 Davy Brion Mon, 13 Oct 2008 05:05:51 +0000 http://davybrion.com/blog/?p=501#comment-3494 he's probably too busy preparing his Silverlight presentation ;) he’s probably too busy preparing his Silverlight presentation ;)

]]> By: Koenhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3475 Koen Sun, 12 Oct 2008 20:59:48 +0000 http://davybrion.com/blog/?p=501#comment-3475 Did scottgu reply yet? Did scottgu reply yet?

]]> By: Davy Brionhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3422 Davy Brion Sat, 11 Oct 2008 13:29:48 +0000 http://davybrion.com/blog/?p=501#comment-3422 I submitted a bug to Microsoft Connect for this:https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=374919 I submitted a bug to Microsoft Connect for this:

https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=374919

]]> By: Davy Brionhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3387 Davy Brion Fri, 10 Oct 2008 09:30:20 +0000 http://davybrion.com/blog/?p=501#comment-3387 dunno if that's actually causing the problem... especially because it can be reproduced with very simple code in both a unit test environment and a console application (and i really can't imagine some kind of background code in a console application causing different debugger behavior). And the code itself doesn't make any calls to System.Diagnostics.Debugger at all...the thing is... the catch (T exception) is not entered, but the catch (Exception e) is entered. And if you then do a (T)e call, it just works. But since the catch (T exception) is listed before the catch (Exception e), and the exception is indeed of type T, then it should in all cases enter the catch(T exception) clause. dunno if that’s actually causing the problem… especially because it can be reproduced with very simple code in both a unit test environment and a console application (and i really can’t imagine some kind of background code in a console application causing different debugger behavior). And the code itself doesn’t make any calls to System.Diagnostics.Debugger at all…

the thing is… the catch (T exception) is not entered, but the catch (Exception e) is entered. And if you then do a (T)e call, it just works. But since the catch (T exception) is listed before the catch (Exception e), and the exception is indeed of type T, then it should in all cases enter the catch(T exception) clause.

]]> By: Patrickhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3386 Patrick Fri, 10 Oct 2008 09:17:46 +0000 http://davybrion.com/blog/?p=501#comment-3386 Check the following link for the solution: http://blogs.msdn.com/jmstall/archive/2004/10/02/236942.aspxThe relevant portion is copied below.User checks: The biggest culprit: A program can explicitly call System.Diagnostics.Debugger.IsAttached to ask if a managed debugger is attached and then behave differently. (The win32 API IsDebuggerPresent() similarly checks for if a native debugger is attached.). This is the easiest way to cause the most pain. For example, WinForms will explicitly use a different 'debuggable' WndProc if a managed debugger is attached. This debuggable wndproc has an extra try-catch around user callbacks (which the non-debuggable wndproc does not have) to notify users if their callbacks are throwing exceptions. Another favorite seems to be throwing exceptions iff a debugger is attached as way of notifying the user. Check the following link for the solution: http://blogs.msdn.com/jmstall/archive/2004/10/02/236942.aspx

The relevant portion is copied below.

User checks: The biggest culprit: A program can explicitly call System.Diagnostics.Debugger.IsAttached to ask if a managed debugger is attached and then behave differently. (The win32 API IsDebuggerPresent() similarly checks for if a native debugger is attached.). This is the easiest way to cause the most pain. For example, WinForms will explicitly use a different ‘debuggable’ WndProc if a managed debugger is attached. This debuggable wndproc has an extra try-catch around user callbacks (which the non-debuggable wndproc does not have) to notify users if their callbacks are throwing exceptions. Another favorite seems to be throwing exceptions iff a debugger is attached as way of notifying the user.

]]> By: den Benhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3384 den Ben Fri, 10 Oct 2008 08:06:28 +0000 http://davybrion.com/blog/?p=501#comment-3384 Hmms... this truly is a challenge. And I was so hoping to be your Hero Of The Week :pFact is: Google isn't going to be much of a help either. When you search for: "catch (T " debugger 3.5...this article is at the top of the list ;-) Hmms… this truly is a challenge. And I was so hoping to be your Hero Of The Week :p

Fact is: Google isn’t going to be much of a help either. When you search for: “catch (T ” debugger 3.5

…this article is at the top of the list ;-)

]]> By: Davy Brionhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3383 Davy Brion Fri, 10 Oct 2008 07:47:37 +0000 http://davybrion.com/blog/?p=501#comment-3383 nope, resharper runs the tests without the debugger by default, so it doesn't need it... it can just listen to the proper events from the nunit testrunner classes to get all of that information :)it can't be resharper because i just remembered that i also have the problem when running the tests with the Testdriven.NET (with the debugger enabled) nope, resharper runs the tests without the debugger by default, so it doesn’t need it… it can just listen to the proper events from the nunit testrunner classes to get all of that information :)

it can’t be resharper because i just remembered that i also have the problem when running the tests with the Testdriven.NET (with the debugger enabled)

]]> By: den Benhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3382 den Ben Fri, 10 Oct 2008 07:44:05 +0000 http://davybrion.com/blog/?p=501#comment-3382 <cite>"but does resharper even have an impact on the debugger?"</cite>I believe it has to be able to mingle with it for at least some part. How else would it be able to show that pretty little tests running progress? “but does resharper even have an impact on the debugger?”

I believe it has to be able to mingle with it for at least some part. How else would it be able to show that pretty little tests running progress?

]]> By: Davy Brionhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3379 Davy Brion Fri, 10 Oct 2008 06:38:18 +0000 http://davybrion.com/blog/?p=501#comment-3379 @Alexglad we're not the only ones seeing this problem :)@Billinteresting... my setup is the following: .NET 3.5 SP1 Visual Studio 2008 9.0.30729.1 SP Resharper 4.1.933.3i've experienced it on 2 pc's at work, both with the same configuration (the one listed above + windows vista business), and also on my home pc which has XP SP3So i guess the only difference (on first sight) is the resharper version... but does resharper even have an impact on the debugger? @Alex

glad we’re not the only ones seeing this problem :)

@Bill

interesting… my setup is the following:
.NET 3.5 SP1
Visual Studio 2008 9.0.30729.1 SP
Resharper 4.1.933.3

i’ve experienced it on 2 pc’s at work, both with the same configuration (the one listed above + windows vista business), and also on my home pc which has XP SP3

So i guess the only difference (on first sight) is the resharper version… but does resharper even have an impact on the debugger?

]]> By: Alex Simkinhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3368 Alex Simkin Thu, 09 Oct 2008 20:18:45 +0000 http://davybrion.com/blog/?p=501#comment-3368 I confirm. When stepping through in the debugger, the exception is caught by:"catch (Exception ex)" and not by "catch (T ex)" even though type of ex is ExceptionWeirdness.MyException I confirm. When stepping through in the debugger, the exception is caught by:

“catch (Exception ex)” and not by “catch (T ex)” even though type of ex is ExceptionWeirdness.MyException

]]> By: Bill Piercehttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3367 Bill Pierce Thu, 09 Oct 2008 19:09:54 +0000 http://davybrion.com/blog/?p=501#comment-3367 I have: .Net 3.5 SP1 VS 2008 9.0.30729.1 SP ReSharper 3.1 C# Edition 3.1.584.3I copied and pasted your test exactly and do not experience the problem when running the test normally, with a debugger attached and no breakpoints, or by stepping through the test in the debugger. Did not attempt debugging a console app.Perhaps try adding the serialization constructor to MyException. I have:
.Net 3.5 SP1
VS 2008 9.0.30729.1 SP
ReSharper 3.1 C# Edition 3.1.584.3

I copied and pasted your test exactly and do not experience the problem when running the test normally, with a debugger attached and no breakpoints, or by stepping through the test in the debugger. Did not attempt debugging a console app.

Perhaps try adding the serialization constructor to MyException.

]]> By: Dew Drop - October 9, 2008 | Alvin Ashcraft's Morning Dewhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3360 Dew Drop - October 9, 2008 | Alvin Ashcraft's Morning Dew Thu, 09 Oct 2008 13:58:29 +0000 http://davybrion.com/blog/?p=501#comment-3360 [...] Exceptional Exception Handling Behavior (Davy Brion) [...] [...] Exceptional Exception Handling Behavior (Davy Brion) [...]

]]> By: Davy Brionhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3359 Davy Brion Thu, 09 Oct 2008 13:33:06 +0000 http://davybrion.com/blog/?p=501#comment-3359 that's good to know... i've only tried it with visual studio 2008 sp1 so it might have been introduced by the service pack somehow that’s good to know… i’ve only tried it with visual studio 2008 sp1 so it might have been introduced by the service pack somehow

]]> By: Fabricehttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3358 Fabrice Thu, 09 Oct 2008 13:31:31 +0000 http://davybrion.com/blog/?p=501#comment-3358 Seems strange. It works well with .NET 2.0. I tried with VS 2005, and in both cases (debugging or not), it works as expected. Seems strange. It works well with .NET 2.0. I tried with VS 2005, and in both cases (debugging or not), it works as expected.

]]> By: Reflective Perspective - Chris Alcock » The Morning Brew #197http://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3345 Reflective Perspective - Chris Alcock » The Morning Brew #197 Thu, 09 Oct 2008 07:20:01 +0000 http://davybrion.com/blog/?p=501#comment-3345 [...] Exceptional Exception Handling Behavior - Davy Brion posts about some strange behaviour with exceptions and generics in and out of the debugger. Davy has posed this as a question, so the answer to the problem may be in the comments by the time you read this. [...] [...] Exceptional Exception Handling Behavior – Davy Brion posts about some strange behaviour with exceptions and generics in and out of the debugger. Davy has posed this as a question, so the answer to the problem may be in the comments by the time you read this. [...]

]]> By: Exceptional exception handling - KoenVhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3325 Exceptional exception handling - KoenV Wed, 08 Oct 2008 18:04:29 +0000 http://davybrion.com/blog/?p=501#comment-3325 [...] colleague Davy beat me to post this problem we had today at work, so I'm gonna be lazy and link to him (and steal his title).Btw yesterday we applied this "solution" to one of our biggest projects and [...] [...] colleague Davy beat me to post this problem we had today at work, so I’m gonna be lazy and link to him (and steal his title).Btw yesterday we applied this “solution” to one of our biggest projects and [...]

]]> By: Davy Brionhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3324 Davy Brion Wed, 08 Oct 2008 17:51:14 +0000 http://davybrion.com/blog/?p=501#comment-3324 don't think that makes a difference... the really weird thing is that when the debugger is not attached, the exception is caught by the catch (T exception) handler. When it is attached, the catch (T exception) handler is just not entered.Yet, when you put in the catch (Exception exception) handler, and cast the exception to T, it does work when the debugger is attached.it's as if catching exceptions just behaves differently when a debugger is attached... i tried it on 3 different PC's before i believed it :) don’t think that makes a difference… the really weird thing is that when the debugger is not attached, the exception is caught by the catch (T exception) handler. When it is attached, the catch (T exception) handler is just not entered.

Yet, when you put in the catch (Exception exception) handler, and cast the exception to T, it does work when the debugger is attached.

it’s as if catching exceptions just behaves differently when a debugger is attached… i tried it on 3 different PC’s before i believed it :)

]]> By: JacobMhttp://davybrion.com/blog/2008/10/exceptional-exception-handlingbehavior/comment-page-1/#comment-3323 JacobM Wed, 08 Oct 2008 17:39:52 +0000 http://davybrion.com/blog/?p=501#comment-3323 You may want to check the "Break on exceptions" settings in the VS debugger -- you can certainly set it to break on any exception, even if it's handled. Not what you want in this case. You may want to check the “Break on exceptions” settings in the VS debugger — you can certainly set it to break on any exception, even if it’s handled. Not what you want in this case.

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