[Bug libstdc++/87846] std::filesystem::create_directories with a path with a trailing slash does not create any directory

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87846

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Author: redi
Date: Thu Nov 29 00:39:37 2018
New Revision: 266598

URL: https://gcc.gnu.org/viewcvs?rev=266598&root=gcc&view=rev
Log:
PR libstdc++/86910 fix filesystem::create_directories

Implement the proposed semantics from P1164R0, which reverts the changes
of LWG 2935. This means that failure to create a directory because a
non-directory already exists with that name will be reported as an
error.

While rewriting the function, also fix PR 87846, which is a result of
the C++17 changes to how a trailing slash on a path affects the last
component of a path.

        PR libstdc++/86910
        PR libstdc++/87846
        * src/filesystem/ops.cc (experimental::create_directories): Report
        an error when the path resolves to an existing non-directory (P1164).
        * src/filesystem/std-ops.cc (create_directories): Likewise. Handle
        empty filenames due to trailing slashes.
        * testsuite/27_io/filesystem/operations/create_directories.cc: Test
        when some component of the path exists and is not a directory. Test
        trailing slashes.
        * testsuite/experimental/filesystem/operations/create_directories.cc:
        Likewise.

Modified:
    trunk/libstdc++-v3/ChangeLog
    trunk/libstdc++-v3/src/filesystem/ops.cc
    trunk/libstdc++-v3/src/filesystem/std-ops.cc
   
trunk/libstdc++-v3/testsuite/27_io/filesystem/operations/create_directories.cc
   
trunk/libstdc++-v3/testsuite/experimental/filesystem/operations/create_directories.cc