id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
3361,[Program Options] Bug: empty arguments treated as positional ones,k-r.ernst@…,Vladimir Prus,"Tested with boost::program_options in 1.39

When an program argument is empty, or contains only whitespace, it it treated as positional argument,  confusing program_options

How to reproduce:

1. Get example app which expects 1 positional argument

2. launch it with e.g. execlp(""testapp"", ""testapp"", """", ""real_positional_argument"", NULL);

Observed behavior:
Error: ""too many positional options""

Expected behavior:
Empty argument should be ignored

Additional note:
instead of empty string """", the same error happens with only whitespace like "" """,Bugs,closed,Boost 1.40.0,program_options,Boost 1.39.0,Problem,invalid,program options whitespace positional,