[CMake] Unexpected behavior testing boolean expressions

[Timothy M. Shead]

Folks:

This seems like CMake 101, but I'm running into weird behavior testing
boolean expressions within a macro.  I've reproduced the problem using
both 2.4.7 and CVS trunk on Gentoo Linux, presumably it is some subtlety
that I just don't get :)

If I run the following:

	set(var YES)

	if(var)
        	message("true")
	else(var)
        	message("false")
	endif(var)

I get the expected result:

	true

This produces expected results for all of the documented "boolean"
values: YES, NO, TRUE, FALSE, ON, OFF, etc.  However, if I pass one of
those values to a macro:

	macro(test var)
	        if(${var})
	                message("true")
	        else(${var})
	                message("false")
	        endif(${var})
	endmacro(test)

	test(1)
	test(0)
	test(YES)
	test(NO)
	test(TRUE)
	test(FALSE)
	test(ON)
	test(OFF)

Things look pretty strange to me:

	true
	false
	false
	false
	false
	false
	false
	false

... only "1" tests true!  Can anyone shed some light on where I'm going
wrong?

Thanks in advance,
Tim