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NullReferenceException in IISHttpContext

See original GitHub issue

Describe the bug

Since updating a website running in Azure App Service to use ASP.NET Core 2.2.0 with in-process hosting, I’ve observed a small number of NullReferenceExceptions being thrown via Application Insights.

System.NullReferenceException:
   at Microsoft.AspNetCore.Server.IIS.Core.IISHttpContext.GetOriginalPath (Microsoft.AspNetCore.Server.IIS, Version=2.2.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
   at Microsoft.AspNetCore.Server.IIS.Core.IISHttpContext.InitializeContext (Microsoft.AspNetCore.Server.IIS, Version=2.2.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
   at Microsoft.AspNetCore.Server.IIS.Core.IISHttpContextOfT`1+<ProcessRequestAsync>d__2.MoveNext (Microsoft.AspNetCore.Server.IIS, Version=2.2.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.AspNetCore.Server.IIS.Core.IISHttpServer+<HandleRequest>d__27.MoveNext (Microsoft.AspNetCore.Server.IIS, Version=2.2.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)

To Reproduce

Application experiencing the issue was built from this commit: martincostello/website@ee2ca4ba02823b97062924b7dc8f313e6278a3f8

Expected behavior

HTTP request is processed successfully.

Screenshots

Additional context

Add any other context about the problem here. Include the output of dotnet --info

Issue Analytics

State:
Created 5 years ago
Reactions:14
Comments:38 (21 by maintainers)

Top GitHub Comments

9reactions

mxwlfcommented, Sep 5, 2019

If I understand this thread correctly, we are supposed to wait for another release and in the meantime this is not causing any harm. But it is really distracting to see these false positives where we expect to see only “real” exceptions. Is there some middleware that you can provide to catch this condition? I do not want to filter this on my side, for fear of eating up an authentic failure. TIA

8reactions

jeremycookcommented, Apr 23, 2019

I’m glad this will be addressed in 3.0 but will this be addressed in 2.2.x or 2.x?

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