mkfifoat: Work around trailing slash bug in mkfifoat() on AIX 7.2.

* m4/mkfifoat.m4 (gl_FUNC_MKFIFOAT): Add a test whether mkfifoat rejects
trailing slashes. Set REPLACE_MKFIFOAT if not.
* lib/sys_stat.in.h (mkfifoat): Consider REPLACE_MKFIFOAT.
* lib/mkfifoat.c: Add an overriding implementation of mkfifoat().
* m4/sys_stat_h.m4 (gl_SYS_STAT_H_DEFAULTS): Initialize
REPLACE_MKFIFOAT.
* modules/sys_stat (Makefile.am): Substitute REPLACE_MKFIFOAT.
* modules/mkfifoat (Depends-on): Add fstatat.
(configure.ac): Consider REPLACE_MKFIFOAT.
* doc/posix-functions/mkfifoat.texi: Mention the AIX bug.

1 files changed, 51 insertions, 13 deletions

diff --git a/lib/mkfifoat.c b/lib/mkfifoat.c
index 65c43b6424..785a1a7617 100644
--- a/lib/mkfifoat.c
+++ b/lib/mkfifoat.c
@@ -23,9 +23,45 @@
 
 #include <stdlib.h>
 
-#if !HAVE_MKFIFO
+#if HAVE_MKFIFOAT
 
 # include <errno.h>
+# include <fcntl.h>
+# include <string.h>
+
+int
+rpl_mkfifoat (int fd, char const *file, mode_t mode)
+#undef mkfifoat
+{
+  /* Use the original mkfifoat(), but correct the trailing slash handling.  */
+  size_t len = strlen (file);
+  if (len && file[len - 1] == '/')
+    {
+      struct stat st;
+
+      if (fstatat (fd, file, &st, AT_SYMLINK_NOFOLLOW) < 0)
+        {
+          if (errno == EOVERFLOW)
+            /* It's surely a file, not a directory.  */
+            errno = ENOTDIR;
+        }
+      else
+        {
+          /* It's a directory, otherwise fstatat() would have reported an error
+             ENOTDIR.  */
+          errno = EEXIST;
+        }
+      return -1;
+    }
+
+  return mkfifoat (fd, file, mode);
+}
+
+#else
+
+# if !HAVE_MKFIFO
+
+#  include <errno.h>
 
 /* Mingw lacks mkfifo, so this wrapper is trivial.  */
 
@@ -37,7 +73,7 @@ mkfifoat (int fd _GL_UNUSED, char const *path _GL_UNUSED,
   return -1;
 }
 
-#else /* HAVE_MKFIFO */
+# else /* HAVE_MKFIFO */
 
 /* Create a named fifo FILE relative to directory FD, with access
    permissions in MODE.  If possible, do it without changing the
@@ -45,14 +81,16 @@ mkfifoat (int fd _GL_UNUSED, char const *path _GL_UNUSED,
    then mkfifo/restore_cwd.  If either the save_cwd or the restore_cwd
    fails, then give a diagnostic and exit nonzero.  */
 
-# define AT_FUNC_NAME mkfifoat
-# define AT_FUNC_F1 mkfifo
-# define AT_FUNC_POST_FILE_PARAM_DECLS , mode_t mode
-# define AT_FUNC_POST_FILE_ARGS        , mode
-# include "at-func.c"
-# undef AT_FUNC_NAME
-# undef AT_FUNC_F1
-# undef AT_FUNC_POST_FILE_PARAM_DECLS
-# undef AT_FUNC_POST_FILE_ARGS
-
-#endif /* HAVE_MKFIFO */
+#  define AT_FUNC_NAME mkfifoat
+#  define AT_FUNC_F1 mkfifo
+#  define AT_FUNC_POST_FILE_PARAM_DECLS , mode_t mode
+#  define AT_FUNC_POST_FILE_ARGS        , mode
+#  include "at-func.c"
+#  undef AT_FUNC_NAME
+#  undef AT_FUNC_F1
+#  undef AT_FUNC_POST_FILE_PARAM_DECLS
+#  undef AT_FUNC_POST_FILE_ARGS
+
+# endif /* HAVE_MKFIFO */
+
+#endif /* HAVE_MKFIFOAT */