fopen: document mingw bug on directories

* doc/posix-functions/fopen.texi (fopen): Mention mingw bug for
not allowing a stream visiting a directory, even though reading
from such a stream is not portable.

Signed-off-by: Eric Blake <ebb9@byu.net>

diff --git a/ChangeLog b/ChangeLog
index 3dfc1c44b71c810019c4616f4593b83c045cf150..38dd15e83fdbc5fa7ee0fd065c0b44da138de089 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2008-09-23  Eric Blake  <ebb9@byu.net>
+
+       fopen: document mingw bug on directories
+       * doc/posix-functions/fopen.texi (fopen): Mention mingw bug for
+       not allowing a stream visiting a directory, even though reading
+       from such a stream is not portable.
+
 2008-09-23  Paolo Bonzini  <bonzini@gnu.org>
 
        * lib/poll.c: Rewrite.

diff --git a/doc/posix-functions/fopen.texi b/doc/posix-functions/fopen.texi
index da6acde58e8b21e7adbc7bf5145699fb98125c73..442d1b66592dcac3b80949a8b3a7e4420e2119d6 100644 (file)
--- a/doc/posix-functions/fopen.texi
+++ b/doc/posix-functions/fopen.texi
@@ -26,4 +26,10 @@ upon failure.
 On Windows, this function returns a file stream in ``text'' mode by default;
 this means that it translates @code{'\n'} to CR/LF by default.  Use the
 @code{"b"} flag if you need reliable binary I/O.
+@item
+On Windows platforms (excluding Cygwin), this function fails to open
+directories for reading.  Such streams have implementation-defined
+semantics on other platforms.  To avoid directory streams with a
+consistent error message, use @code{fstat} after @code{open} and
+@code{fdopen}, rather than @code{fopen} and @code{fileno}.
 @end itemize