Stephen Kelly authored Oct 04, 2012 and Brad King committed Oct 09, 2012

Otherwise the comma is treated as plain text by ParseContent.

$<STREQUAL:,> should be valid and true.
$<STREQUAL:,something> should be valid and false.

$<STREQUAL:,,> should be non-valid as it is 3 parameters.
$<STREQUAL:something,,> should be non-valid as it is 3 parameters.

Additionally, this allows reporting the correct error for other
expressions. For example $<TARGET_PROPERTY:,> should be invalid
because it has an empty target and empty property. It shouldn't
attempt to read the property ',' on the 'implicit this' target.