split_winmain misses last argument if it is empty

[anonymous]

When passing an empty quoted string as last argument to split_winmain, it is not in the returned vector (unless there is a trailing space).

Example:
assert(split_winmain("arg0 \"\"").size() == 2); FAILS (.size() == 1)
assert(split_winmain("arg0 \"\" ").size() == 2); OK

I appended a quick and dirty patch that should fix this.

btw. I don't know if this is actually a problem for program_options type of command lines, I noticed this when I was using the split_winmain only.

[Sascha Ochsenknecht]

(In [59437]) fix in winmain, Fixes #3879