fix lint error in wgettext()

Cppcheck was complaining about the `return val.c_str()` at the end of the
`wgettext()` function. That would normally a bug since the lifetime of
`val` ends when the function returns. In this particular case that's not
true because the string is interned in a cache. Nonetheless, rather than
suppress the lint warning I decided to modify the API to be more idiomatic.

In the process of fixing the aforementioned lint warning I fixed several other
lint errors in that module.

This required making our copy of `wgetopt()` compatible with the rest of
the fish code. Specifically, by removing its local definitions of the
"_" macro so it uses the same macro used everywhere else in the fish
code. The sooner we kill the use of wide chars the better.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/wutil.h b/src/wutil.h
index 9fc61096..b5c77870 100644
--- a/src/wutil.h
+++ b/src/wutil.h
@@ -84,7 +84,7 @@ std::wstring wbasename(const std::wstring &path);
 /// gettext function, wgettext takes care of setting the correct domain, etc. using the textdomain
 /// and bindtextdomain functions. This should probably be moved out of wgettext, so that wgettext
 /// will be nothing more than a wrapper around gettext, like all other functions in this file.
-const wchar_t *wgettext(const wchar_t *in);
+const wcstring &wgettext(const wchar_t *in);
 
 /// Wide character version of mkdir.
 int wmkdir(const wcstring &dir, int mode);