[Bug libstdc++/70609] std::experimental::filesystem::copy fails if the file size is 0 bytes

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70609

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Author: redi
Date: Wed May 25 15:42:40 2016
New Revision: 236711

URL: https://gcc.gnu.org/viewcvs?rev=236711&root=gcc&view=rev
Log:
libstdc++/70609 fix filesystem::copy()

Backport from mainline
2016-04-19  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/70609
        * src/filesystem/ops.cc (close_fd): New function.
        (do_copy_file): Set permissions before copying file contents. Check
        result of closing file descriptors. Don't copy streambuf when file
        is empty.
        (copy(const path&, const path&, copy_options, error_code&)): Use
        lstat for source file when copy_symlinks is set.
        * testsuite/experimental/filesystem/operations/copy.cc: Test copy().

Modified:
    branches/gcc-5-branch/libstdc++-v3/ChangeLog
    branches/gcc-5-branch/libstdc++-v3/src/filesystem/ops.cc
   
branches/gcc-5-branch/libstdc++-v3/testsuite/experimental/filesystem/operations/copy.cc