[CMake] Ignoring return codes on ADD_CUSTOM_COMMAND (hhc.exe)

[Stefan Buschmann]

Hi all,

I'm currently having a problem using the HTMLHelp Compiler (hhc.exe) in 
my CMake-Scripts. I build the doxygen docs, then call hhc.exe and the 
.chm file is created correctly.
But hhc.exe seems to return an error code, so the build has failed and 
my post-build commands are not invoked.

1) Did anyone have similar problems with hhc.exe? Any ideas why hhc.exe 
is returning an error code although the .chm file is generated correctly 
and there are no error messages on the output?
2) Is there a way to tell ADD_CUSTOM_COMMAND to ignore the return value 
of the process and consider it as always successfull?

Thanks,

Stefan