[CMake] ccmake gets all squirrelly over which C++ compiler to use.

[Bill Hoffman]

kent williams wrote:
> So the problem with CCMake forgetting valid user input stems from the
> entire CMakeCache.txt file getting deleted if there's a compiler
> mismatch?
> 
> 

Yes, that is what happens.  The use case that this was supposed to 
address was this:

ccmake ../source
- oops, I did not want that commpiler
- I change CMAKE_C_COMPILER and CMAKE_CXX_COMPILER
- I hit configure again, the cache is wiped except for the new 
CMAKE_C_COMPILER and CMAKE_CXX_COMPILER that you just picked


The problem happens with vtk/itk force compiler stuff:

ccmake ../source
- configure
- tell it where vtk is, vtk changes the compiler
- my code things the user changed the compiler
- everything is wiped except for the C and CXX compilers

VTK/ITK should not change the compiler.


-Bill