Visual Studio 2012 object state corrupted while dubugger is attached

Visual Studio 2012 object state corrupted while dubugger is attached by Jared Grabill

Resolved

as Not Reproducible Help for as Not Reproducible

Type:	Bug
ID:	776259
Opened:	1/10/2013 8:36:13 AM
Access Restriction:	Public

Workaround(s)

view

User(s) can reproduce this bug

In a .Net 4.0 project, incorrect behavior is produced with debugger attached. Only observed on VisualStudio 2012 (2010 works as expected.)

In a class containing a DataTable, and several integer member variables with property accessors, one of the integer properties changes when DataTable.NewRow() is called. After the call, one of the integer properties has a new value (which happens to be a value set on a separate instance of this class.) A breakpoint of the property setter is not hit, nor is the base property ever set directly anywhere in code. Same behavior is exhibited when implemented as an auto-property as well.

This behavior is ONLY shown when the VisualStudio 2012 debugger is attached. The integer property remains correct and unchanged until DataTable.NewRow() is called while debugger is attached, and remains incorrect after the debugger is again detached.

The behavior seems *impossible* and baffled a few developers for the greater part of a day. It is almost as if the class instance is mixed up with another. We attempted to verify that this is not the case by assigning a private readonly Guid in the class constructor to differentiate each instance, but the Guid remained unchanged correctly. To make matters worse, only one developer has been able to recreate this issue on their machine, all with exactly the same source.

The Class is IDisposable, Disposing the DataTable in the class destructor. It is part of the model/view-model used by a new child window instance in our app.

Details (expand)

Visual Studio 2012

1. Create new class Grid implementing IDisposable calling dispose in destructor
2. Add member: DataTable _table and add dispose call in Grid.Dispose()
3. Add int properties: Test1, Test 2
4. Create method AddRow() which calls _table.NewRow() and reads from Test1, Test2
5. Create instance of Grid, set initial value of Test1 to 1
6. Create additional instances with different values of Test1
-
7. Run with debugger attached, observe that Test1’s value has been changed incorrectly to the value contained in another instance
8. Run without debugger attached, observe that Test1’s value remains unchanged and correct

English

Windows 7

English

Class members become corrupted when debugger is attached

Class members remain unchanged by debugger

File Name	Submitted By	Submitted On	File Size
SystemInformation.txt	Jared Grabill	1/10/2013	1.09 MB
SystemInformation.txt	Jared Grabill	1/10/2013	1.09 MB

Posted by Microsoft on 1/17/2013 at 2:42 AM

Hi Jared, we'll close this feedback because it is out of date. Please recreate a new feedback if you have not resolved your issue. Thanks.

Posted by Microsoft on 1/16/2013 at 12:26 AM

Hi Jared, we want to remind you we need a demo project. Please reply to us in time. Thanks.

Posted by Microsoft on 1/10/2013 at 5:58 PM

Thank you for submitting feedback on Visual Studio and .NET Framework. In order to efficiently investigate and reproduce this issue, we are requesting a demo project. Please submit this information to us within 4 business days. We look forward to hearing from you with this information.

Posted by Microsoft on 1/10/2013 at 8:51 AM

Thank you for your feedback, we are currently reviewing the issue you have submitted. If this issue is urgent, please contact support directly(http://support.microsoft.com)

Posted by Jared Grabill on 1/10/2013 at 8:38 AM

Run without debugger attached or debug with VisualSudio 2010