From: Bruno Haible <bruno@clisp.org>
Date: Thu, 12 Jun 2008 11:47:37 +0000 (+0200)
Subject: Add a comment.
X-Git-Tag: v0.1~7268
X-Git-Url: http://erislabs.org.uk/gitweb/?a=commitdiff_plain;h=001adc94db55b40012385a852ab7ce16d2e65a6f;p=gnulib.git

Add a comment.
---

diff --git a/lib/open.c b/lib/open.c
index 482136896..e9324af0d 100644
--- a/lib/open.c
+++ b/lib/open.c
@@ -53,6 +53,27 @@ open (const char *filename, int flags, ...)
     }
 
 # 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 withone 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);