Cast Error when using Trace

[drcate]

Thanks for a great implementation of a Redis Session provider!

I found a bug when Trace is enabled (have it at the application level). In web.config
<system.web>
<trace enabled="true" requestLimit="90" pageOutput="false" traceMode="SortByTime" localOnly="false" />
</system.web>

Causes this exception
Exception: System.InvalidCastException
Unable to cast object of type 'System.Collections.Generic.KeyValuePair`2[System.String,System.Object]' to type 'System.String'.

at System.Web.TraceContext.EndRequest()
at System.Web.UI.Page.ProcessRequestEndTrace()
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context)
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at ASP.sobobacasino_default_aspx.ProcessRequest(HttpContext context) in c:\Users\dcate.MARKETMETRIX\AppData\Local\Temp\Temporary ASP.NET Files\root\ec897ff3\55745380\App_Web_qw3cpivu.0.cs:line 0
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

I can run fine with Trace turned off, but it might be needed from time to time.

Thanks,

• Darryl

[leewang0]

Thanks for bringing this to my attention :)

[Uladzimir-Kavaliuk]

The cause of this issue is that TraceContext expects that HttpSessionState would enumerate strings as described here:

/// <summary>
/// Returns an enumerator that can be used to read all the session-state variable names in the current session.
/// </summary>
/// 
/// <returns>
/// An <see cref="T:System.Collections.IEnumerator"/> that can iterate through the variable names in the session-state collection.
/// </returns>
public IEnumerator GetEnumerator()
{
  return this._container.GetEnumerator();
}

But RedisSessionStateItemCollection in fact falls back to Dictionary<string, object> implementation of GetEnumerator().

[MaKCbIMKo]

I've created a pull request which I think should fix this problem.

[Uladzimir-Kavaliuk]

Hi welegan!
could you please revise the Maksim's fix #18 once again?

The issue might prevent from using this library in production systems because with RedisSessionProvider this https://msdn.microsoft.com/en-us/library/system.web.sessionstate.httpsessionstate.getenumerator(v=vs.110).aspx is never gonna work.
Any access to Page.Session.GetEnumerator() would return enumerator by KeyValuePair, not by string as expected.