Fixed CSHARP-273. If isMaster reports both arbiterOnly and passive true, only believe arbiterOnly and set passive to false.

BsonUnitTests/BsonUnitTests.csproj

@@ -181,9 +181,6 @@
       <Install>true</Install>
     </BootstrapperPackage>
   </ItemGroup>
-  <ItemGroup>
-    <None Include="ClassDiagram1.cd" />
-  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.

Driver/Core/MongoServerInstance.cs

@@ -221,6 +221,8 @@ namespace MongoDB.Driver {
                         isSecondary = isMasterResult.Response["secondary", false].ToBoolean();
                         isPassive = isMasterResult.Response["passive", false].ToBoolean();
                         isArbiter = isMasterResult.Response["arbiterOnly", false].ToBoolean();
+                        // workaround for CSHARP-273
+                        if (isPassive && isArbiter) { isPassive = false; }
                         if (!isPrimary && !slaveOk) {
                             throw new MongoConnectionException("Server is not a primary and SlaveOk is false.");
                         }