[&1.6?] Don't display undefined return values in the Console panel when using command line APIs that don't return any value.
[&1.6?] Don't display undefined return values in the Console panel when using command line APIs that don't return any value.

http://code.google.com/p/fbug/source/detail?r=7905

firebug/tracing-console,firebug/tracing-console