Avoid a compilation warning.

[gnulib.git] / lib / open.c

diff --git a/lib/open.c b/lib/open.c
index a52bf93..13af274 100644 (file)
--- a/lib/open.c
+++ b/lib/open.c
@@ -1,5 +1,5 @@
 /* Open a descriptor to a file.
-   Copyright (C) 2007 Free Software Foundation, Inc.
+   Copyright (C) 2007-2008 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
@@ -18,22 +18,32 @@
 
 #include <config.h>
 
-/* Specification.  */
+/* Get the original definition of open.  It might be defined as a macro.  */
+#define __need_system_fcntl_h
 #include <fcntl.h>
+#undef __need_system_fcntl_h
+#include <sys/types.h>
 
-/* If the fchdir replacement is used, open() is defined in fchdir.c.  */
-#ifndef FCHDIR_REPLACEMENT
+static inline int
+orig_open (const char *filename, int flags, mode_t mode)
+{
+  return open (filename, flags, mode);
+}
 
-# include <stdarg.h>
-# include <string.h>
-# include <sys/types.h>
-# include <sys/stat.h>
+/* Specification.  */
+#include <fcntl.h>
+
+#include <errno.h>
+#include <stdarg.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
 
 int
 open (const char *filename, int flags, ...)
-# undef open
 {
   mode_t mode;
+  int fd;
 
   mode = 0;
   if (flags & O_CREAT)
@@ -51,11 +61,80 @@ open (const char *filename, int flags, ...)
       va_end (arg);
     }
 
-# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
   if (strcmp (filename, "/dev/null") == 0)
     filename = "NUL";
-# endif
+#endif
 
-  return open (filename, flags, mode);
-}
+#if OPEN_TRAILING_SLASH_BUG
+  /* If the filename ends in a slash and one of O_CREAT, O_WRONLY, O_RDWR
+     is specified, then fail.
+     Rationale: POSIX <http://www.opengroup.org/susv3/basedefs/xbd_chap04.html>
+     says that
+       "A pathname that contains at least one non-slash character and that
+        ends with one or more trailing slashes shall be resolved as if a
+        single dot character ( '.' ) were appended to the pathname."
+     and
+       "The special filename dot shall refer to the directory specified by
+        its predecessor."
+     If the named file already exists as a directory, then
+       - if O_CREAT is specified, open() must fail because of the semantics
+         of O_CREAT,
+       - if O_WRONLY or O_RDWR is specified, open() must fail because POSIX
+         <http://www.opengroup.org/susv3/functions/open.html> says that it
+         fails with errno = EISDIR in this case.
+     If the named file does not exist or does not name a directory, then
+       - if O_CREAT is specified, open() must fail since open() cannot create
+         directories,
+       - if O_WRONLY or O_RDWR is specified, open() must fail because the
+         file does not contain a '.' directory.  */
+  if (flags & (O_CREAT | O_WRONLY | O_RDWR))
+    {
+      size_t len = strlen (filename);
+      if (len > 0 && filename[len - 1] == '/')
+       {
+         errno = EISDIR;
+         return -1;
+       }
+    }
 #endif
+
+  fd = orig_open (filename, flags, mode);
+
+#if OPEN_TRAILING_SLASH_BUG
+  /* If the filename ends in a slash and fd does not refer to a directory,
+     then fail.
+     Rationale: POSIX <http://www.opengroup.org/susv3/basedefs/xbd_chap04.html>
+     says that
+       "A pathname that contains at least one non-slash character and that
+        ends with one or more trailing slashes shall be resolved as if a
+        single dot character ( '.' ) were appended to the pathname."
+     and
+       "The special filename dot shall refer to the directory specified by
+        its predecessor."
+     If the named file without the slash is not a directory, open() must fail
+     with ENOTDIR.  */
+  if (fd >= 0)
+    {
+      size_t len = strlen (filename);
+      if (len > 0 && filename[len - 1] == '/')
+       {
+         struct stat statbuf;
+
+         if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode))
+           {
+             close (fd);
+             errno = ENOTDIR;
+             return -1;
+           }
+       }
+    }
+#endif
+
+#ifdef FCHDIR_REPLACEMENT
+  if (fd >= 0)
+    _gl_register_fd (fd, filename);
+#endif
+
+  return fd;
+}