shell (bash) non-empty string test works without -n

[GoogleCodeExporter]

The following warning is wrong:
https://code.google.com/p/google-styleguide/source/browse/trunk/shell.xml?r=112#
716

[[ "${my_var}" ]] is, when quoted, always exactly the same as [[ -n "${my_var}" 
]] regardless of my_var contents, as far I've tested. Even with [ builtin. Can 
you provide a counterexample?

Original issue reported on code.google.com by [email protected] on 9 Nov 2013 at 3:37