Wrong evaluation of conditional properties

I stumbled across a problem in a fairly complex project with conditional properties. Unfortunalty I do not have a simplified project to reproduce this issue but when I find some time I will try to set one up.

The issue boils down to a property sheet defining a property like this

<Choose>  
  <When Condition=some_cond>
    <PropertyGroup>
      <P1>Foo</P1>
    </PropertyGroup>
  </When>
  <Otherwise>
    <PropertyGroup>
      <P1>Bar</P1>
    </PropertyGroup>
  </Otherwise>
</Choose>

If the condition is true everything works fine but when the condition is evaluated to false it seems that in SanitizeProjectNode the when node is scheduled for deletion but before this is done the Otherwise node is evaluated and discarded because the when node is still present. The attached diff fixes the issue for me but I wonder if this might break other thing I did not find yet. delay_node_process_diff.txt

[mkaes]

I finally was able to make an example project. It is possible to build the x86 and x64 config with visual studio but the clang tools always take the wrong condition. In this case a non valid path and thus a compile error. I hope this helps. PropsTest.zip

[mkaes]

It still does not work with the 4.10 version without my patch. So I guess there is still something wrong. I was not yet able to strip our build system to an easily debuggable example. But as soon as I understand msbuild good enough to do so, I will reopen this bug.