[CMake] cmake out of source build writes build files at source dirs?

[Claus Klein]

Today, I discovered than in the special case of a substituted  
PROJECT_SOURCE_DIR,
all build files for subdir packages are created in PROJECT_SOURCE_DIR  
and not at the PROJECT_BINARY_DIR.

I use windows cmd shell
	 subst w: z:/some/deep/path/to/source/dir

Than I create a new build dir:

cd /d w:/
mkdir build
cd build
cmake ..


after that, all subdirs of the source dir are created as
w:/build<subdir1>
w:/build<subdir2>
...
filled with the cmake build files.

I tested cmake 2.8.0, 2.8.1 and 2.8.2 version. all have the same  
behaviour!
The created project builds fine too.

It seems that the PROJECT_BINARY_DIR and the subdir paths are  
concatenated without a path separator.

Claus