slide/mono — comment on commit 407dd029e3f1ec712a7f6a8b684b8ee8d2a18b61
File: mcs/class/Microsoft.Build.Tasks/Microsoft.Build.Tasks/Copy.cs line 207
By slide:

I even ran with the msbuild in the v2.0xxxx directory and it still reset the attributes to Normal if ReadOnly was set at all.