EnsureTrailingSlash differs from HasTrailingSlash

[Forgind]

@yaqiyang reported an issue in which $([MSBuild]::EnsureTrailingSlash('$(MyProp)') was not equivalent to <MyProp Condition=!HasTrailingSlash('$(MyProp)')>$(MyProp)</MyProp>

I don't know in which cases they're equivalent and in which cases they aren't, but it would be good to find out and ideally make them the same.

cc @cdmihai

[Nirmal4G]

The only difference I can see with the latest code is that it replaces the Directory Separator characters to match the platform it's running on.

[Forgind]

It's possible this was fixed in the past few years, so perhaps check to see if the code for one or both methods has been changed since I filed this. Would be nice to close it if so. It's also possible the platform-specific slash logic is wrong. (I didn't look at it before writing this.)