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  1. Log4net
  2. LOG4NET-393

Using dynamic methods with log4net causes NullReferenceException in StackFrameItem

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Details

    • Bug
    • Status: Resolved
    • Blocker
    • Resolution: Fixed
    • 1.2.12
    • 1.2.13
    • Core
    • None
    • VS2012, Windows 7

    Description

      In our production code we use dynamic methods e.g. when using the factory pattern. We upgraded from 1.2.10 to 1.2.12 and encountered the following exception:

      log4net:ERROR An exception ocurred while retreiving stack frame information.
      System.NullReferenceException: Object reference not set to an instance of an object.
      at log4net.Core.StackFrameItem..ctor(StackFrame frame) in c:\Users\wilfred.dittmer\Documents\Visual Studio 2012\Projects\Log4netLambaExpressionTest\log4net-1.2.12-src\log4net-1.2.12\src\Core\StackFrameItem.cs:line 61

      I created a test project (attached) which shows the exception occuring.
      If the method is:

      {System.Object lambda_method(System.Runtime.CompilerServices.Closure)}

      then one cannot access the DeclaringType. The code then tries to get the FullName of the null value which causes the exception.

      According to: http://msdn.microsoft.com/en-us/library/system.reflection.emit.dynamicmethod.declaringtype.aspx

      "DynamicMethod.DeclaringType: Gets the type that declares the method, which is always null for dynamic methods."

      So it seems best to check if DeclaringType is null and if so leave the m_className set to 'NA'.

      Attachments

        1. Log4netLambaExpressionTest.zip
          1.51 MB
          W.R. Dittmer

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            Unassigned Unassigned
            wdittmer W.R. Dittmer
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              Updated:
              Resolved: