From 8346ecd045f052983f69eb2c1d39e89e911aed87 Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Thu, 12 Jun 2008 02:17:36 +0200
Subject: [PATCH] Work around open() bug on HP-UX 11 and Solaris 9.

---
 ChangeLog                     |  9 +++++++++
 doc/posix-functions/open.texi |  4 ++++
 lib/open.c                    | 15 ++++++++++++++-
 m4/open.m4                    | 39 +++++++++++++++++++++++++++++++++++++--
 tests/test-open.c             |  2 ++
 5 files changed, 66 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 0e6fdf69b..38b642dea 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2008-06-11  Bruno Haible  <bruno@clisp.org>
+
+	* m4/open.m4 (gl_FUNC_OPEN): Add test against trailing slash bug.
+	* lib/open.c: Include errno.h.
+	(open): Fail when attempting to write to a file that has a trailing
+	slash.
+	* tests/test-open.c (main): Test against trailing slash bug.
+	* doc/posix-functions/open.texi: Mention the trailing slash bug.
+
 2008-06-10  Bruno Haible  <bruno@clisp.org>
 
 	* tests/test-vc-list-files-git.sh: Make double use of 'exit'. Needed
diff --git a/doc/posix-functions/open.texi b/doc/posix-functions/open.texi
index 7a6d5fc76..bb982cfae 100644
--- a/doc/posix-functions/open.texi
+++ b/doc/posix-functions/open.texi
@@ -9,6 +9,10 @@ Gnulib module: open
 Portability problems fixed by Gnulib:
 @itemize
 @item
+This function does not fail when the file name argument ends in a slash
+and (without the slash) names a nonexistent file, on some platforms:
+HP-UX 11.00, Solaris 9.
+@item
 On Windows platforms (excluding Cygwin), this function does usually not
 recognize the @file{/dev/null} filename.
 @end itemize
diff --git a/lib/open.c b/lib/open.c
index a52bf935b..482136896 100644
--- 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
@@ -24,6 +24,7 @@
 /* If the fchdir replacement is used, open() is defined in fchdir.c.  */
 #ifndef FCHDIR_REPLACEMENT
 
+# include <errno.h>
 # include <stdarg.h>
 # include <string.h>
 # include <sys/types.h>
@@ -51,6 +52,18 @@ open (const char *filename, int flags, ...)
       va_end (arg);
     }
 
+# if OPEN_TRAILING_SLASH_BUG
+  if (flags & (O_CREAT | O_WRONLY | O_RDWR))
+    {
+      size_t len = strlen (filename);
+      if (len > 0 && filename[len - 1] == '/')
+	{
+	  errno = EISDIR;
+	  return -1;
+	}
+    }
+# endif
+
 # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
   if (strcmp (filename, "/dev/null") == 0)
     filename = "NUL";
diff --git a/m4/open.m4 b/m4/open.m4
index 90d528ac1..335f4e500 100644
--- a/m4/open.m4
+++ b/m4/open.m4
@@ -1,5 +1,5 @@
-# open.m4 serial 1
-dnl Copyright (C) 2007 Free Software Foundation, Inc.
+# open.m4 serial 2
+dnl Copyright (C) 2007-2008 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -13,5 +13,40 @@ AC_DEFUN([gl_FUNC_OPEN],
       REPLACE_OPEN=1
       AC_LIBOBJ([open])
       ;;
+    *)
+      dnl open("foo/") should not create a file when the file name has a
+      dnl trailing slash.
+      AC_CACHE_CHECK([whether open recognizes a trailing slash],
+        [gl_cv_func_open_slash],
+        [
+          AC_TRY_RUN([
+#include <fcntl.h>
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+int main ()
+{
+  return open ("conftest.sl/", O_CREAT, 0600) >= 0;
+}], [gl_cv_func_open_slash=yes], [gl_cv_func_open_slash=no],
+            [
+changequote(,)dnl
+             case "$host_os" in
+               solaris2.[0-9]*) gl_cv_func_open_slash="guessing no" ;;
+               hpux*)           gl_cv_func_open_slash="guessing no" ;;
+               *)               gl_cv_func_open_slash="guessing yes" ;;
+             esac
+changequote([,])dnl
+            ])
+          rm -f conftest.sl
+        ])
+      case "$gl_cv_func_open_slash" in
+        *no)
+          AC_DEFINE([OPEN_TRAILING_SLASH_BUG], 1,
+            [Define to 1 if open() fails to recognize a trailing slash.])
+          REPLACE_OPEN=1
+          AC_LIBOBJ([open])
+          ;;
+      esac
+      ;;
   esac
 ])
diff --git a/tests/test-open.c b/tests/test-open.c
index c570aaad4..aad36c4ad 100644
--- a/tests/test-open.c
+++ b/tests/test-open.c
@@ -38,6 +38,8 @@
 int
 main ()
 {
+  ASSERT (open ("nonexist.ent/", O_CREAT, 0600) < 0);
+
   ASSERT (open ("/dev/null", O_RDONLY) >= 0);
 
   return 0;
-- 
2.11.0