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+/* Work around an fstatat bug on Solaris 9.
+
+ Copyright (C) 2006, 2009-2023 Free Software Foundation, Inc.
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+/* Written by Paul Eggert and Jim Meyering. */
+
+/* If the user's config.h happens to include <sys/stat.h>, let it include only
+ the system's <sys/stat.h> here, so that orig_fstatat doesn't recurse to
+ rpl_fstatat. */
+#define __need_system_sys_stat_h
+#include <config.h>
+
+/* Get the original definition of fstatat. It might be defined as a macro. */
+#include <sys/types.h>
+#include <sys/stat.h>
+#undef __need_system_sys_stat_h
+
+#if HAVE_FSTATAT && HAVE_WORKING_FSTATAT_ZERO_FLAG
+static int
+orig_fstatat (int fd, char const *filename, struct stat *buf, int flags)
+{
+ return fstatat (fd, filename, buf, flags);
+}
+#endif
+
+#ifdef __osf__
+/* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc
+ eliminates this include because of the preliminary #include <sys/stat.h>
+ above. */
+# include "sys/stat.h"
+#else
+# include <sys/stat.h>
+#endif
+
+#include "stat-time.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if HAVE_FSTATAT && HAVE_WORKING_FSTATAT_ZERO_FLAG
+
+# ifndef LSTAT_FOLLOWS_SLASHED_SYMLINK
+# define LSTAT_FOLLOWS_SLASHED_SYMLINK 0
+# endif
+
+static int
+normal_fstatat (int fd, char const *file, struct stat *st, int flag)
+{
+ return stat_time_normalize (orig_fstatat (fd, file, st, flag), st);
+}
+
+/* fstatat should always follow symbolic links that end in /, but on
+ Solaris 9 it doesn't if AT_SYMLINK_NOFOLLOW is specified.
+ Likewise, trailing slash on a non-directory should be an error.
+ These are the same problems that lstat.c and stat.c address, so
+ solve it in a similar way.
+
+ AIX 7.1 fstatat (AT_FDCWD, ..., 0) always fails, which is a bug.
+ Work around this bug if FSTATAT_AT_FDCWD_0_BROKEN is nonzero. */
+
+int
+rpl_fstatat (int fd, char const *file, struct stat *st, int flag)
+{
+ int result = normal_fstatat (fd, file, st, flag);
+ size_t len;
+
+ if (LSTAT_FOLLOWS_SLASHED_SYMLINK || result != 0)
+ return result;
+ len = strlen (file);
+ if (flag & AT_SYMLINK_NOFOLLOW)
+ {
+ /* Fix lstat behavior. */
+ if (file[len - 1] != '/' || S_ISDIR (st->st_mode))
+ return 0;
+ if (!S_ISLNK (st->st_mode))
+ {
+ errno = ENOTDIR;
+ return -1;
+ }
+ result = normal_fstatat (fd, file, st, flag & ~AT_SYMLINK_NOFOLLOW);
+ }
+ /* Fix stat behavior. */
+ if (result == 0 && !S_ISDIR (st->st_mode) && file[len - 1] == '/')
+ {
+ errno = ENOTDIR;
+ return -1;
+ }
+ return result;
+}
+
+#else /* ! (HAVE_FSTATAT && HAVE_WORKING_FSTATAT_ZERO_FLAG) */
+
+/* On mingw, the gnulib <sys/stat.h> defines 'stat' as a function-like
+ macro; but using it in AT_FUNC_F2 causes compilation failure
+ because the preprocessor sees a use of a macro that requires two
+ arguments but is only given one. Hence, we need an inline
+ forwarder to get past the preprocessor. */
+static int
+stat_func (char const *name, struct stat *st)
+{
+ return stat (name, st);
+}
+
+/* Likewise, if there is no native 'lstat', then the gnulib
+ <sys/stat.h> defined it as stat, which also needs adjustment. */
+# if !HAVE_LSTAT
+# undef lstat
+# define lstat stat_func
+# endif
+
+/* Replacement for Solaris' function by the same name.
+ <https://www.google.com/search?q=fstatat+site:docs.oracle.com>
+ First, try to simulate it via l?stat ("/proc/self/fd/FD/FILE").
+ Failing that, simulate it via save_cwd/fchdir/(stat|lstat)/restore_cwd.
+ If either the save_cwd or the restore_cwd fails (relatively unlikely),
+ then give a diagnostic and exit nonzero.
+ Otherwise, this function works just like Solaris' fstatat. */
+
+# define AT_FUNC_NAME fstatat
+# define AT_FUNC_F1 lstat
+# define AT_FUNC_F2 stat_func
+# define AT_FUNC_USE_F1_COND AT_SYMLINK_NOFOLLOW
+# define AT_FUNC_POST_FILE_PARAM_DECLS , struct stat *st, int flag
+# define AT_FUNC_POST_FILE_ARGS , st
+# include "at-func.c"
+# undef AT_FUNC_NAME
+# undef AT_FUNC_F1
+# undef AT_FUNC_F2
+# undef AT_FUNC_USE_F1_COND
+# undef AT_FUNC_POST_FILE_PARAM_DECLS
+# undef AT_FUNC_POST_FILE_ARGS
+
+#endif /* !HAVE_FSTATAT */