* bootstrap.conf (gnulib_modules): Add c-file-type
and remove file-type.
* po/POTFILES.in: Add lib/c-file-type.c, remove lib/file-type.c
* src/diff.c (O_PATH_DEFINED): New constant.
(detype_from_mode): Remove; no longer used.
(dir_p): Go back to the old way of using S_ISDIR.
(compare_prepped_files): Use filetype and stat macros, not detype.
Pass symlink fd and "" to careadlinkat if available, as that
avoids a race. Test for dir vs file earlier, so that a missing
file is treated consistently with dir/file vs file.
(compare_files): New arg DETYPE replacing the old DETYPE0 and DETYPE1.
All uses changed. st_size for nonexistent files is 0, not -1.
Set up .filetype, not .detype, as .filetype is finer-grained.
Open symlinks with O_PATH on GNU/Linux, since we can then
use readlinkat on the resulting file descriptor and this
avoids a race.
* src/diff.h (struct file_data): Remove detype member.
Add filetype member; it’s finer-grained. All uses changed.
* tests/no-dereference: Add test that the previous commit failed.
* bootstrap.conf (gnulib_modules): Add quote.
* src/diff.c: Include quote.h.
(compare_files): Print contents of symlinks that differ,
and quote their names and contents.
* src/system.h (symlink_size_ok): Remove.
(stat_size): Don’t worry about symlink sizes.
* tests/no-dereference: Adjust tests to match new behavior.
