[Bug libstdc++/88884] std::filesystem::absolute("//") does not produce an absolute path on mingw

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88884

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Author: redi
Date: Thu Jan 17 15:32:05 2019
New Revision: 268035

URL: https://gcc.gnu.org/viewcvs?rev=268035&root=gcc&view=rev
Log:
PR libstdc++/88884 fix filesystem::absolute("//") for mingw

        PR libstdc++/88884
        * src/c++17/fs_ops.cc (absolute(const path&, error_code&)): Do nothing
        if the path is already absolute.
        [_GLIBCXX_FILESYSTEM_IS_WINDOWS]: Normalize root-directory.
        [!_GLIBCXX_FILESYSTEM_IS_WINDOWS]: Pass error_code to current_path.

Modified:
    trunk/libstdc++-v3/ChangeLog
    trunk/libstdc++-v3/src/c++17/fs_ops.cc