From e16cda9ad8dad231d6354c1af2c58a07749e5eca Mon Sep 17 00:00:00 2001
From: "R. David Murray" <rdmurray@bitdance.com>
Date: Fri, 15 Oct 2010 23:12:57 +0000
Subject: [PATCH] #9862: On AIX PIPE_BUF is broken.  Make it 512.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Patch by Sébastien Sablé.
---
 Misc/NEWS              | 3 +++
 Modules/selectmodule.c | 4 ++++
 configure.in           | 4 ++++
 3 files changed, 11 insertions(+)

diff --git a/Misc/NEWS b/Misc/NEWS
index 0e247379fbc..55e57ba3103 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@ What's New in Python 3.2 Beta 1?
 Core and Builtins
 -----------------
 
+- Issue #9862: Compensate for broken PIPE_BUF in AIX by hard coding
+  its value as the default 512 when compiling on AIX.
+
 - Use locale encoding instead of UTF-8 to encode and decode filenames if
   Py_FileSystemDefaultEncoding is not set.
 
diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c
index 5c475f57859..58cc4c7c86a 100644
--- a/Modules/selectmodule.c
+++ b/Modules/selectmodule.c
@@ -1786,6 +1786,10 @@ PyInit_select(void)
     PyModule_AddObject(m, "error", SelectError);
 
 #ifdef PIPE_BUF
+#ifdef HAVE_BROKEN_PIPE_BUF
+#undef PIPE_BUF
+#define PIPE_BUF 512
+#endif
     PyModule_AddIntConstant(m, "PIPE_BUF", PIPE_BUF);
 #endif
 
diff --git a/configure.in b/configure.in
index 01d81e96711..4252d93c4bf 100644
--- a/configure.in
+++ b/configure.in
@@ -4213,6 +4213,10 @@ fi
 ],
 [AC_MSG_RESULT(no value specified)])
 
+case $ac_sys_system in
+AIX*)   
+  AC_DEFINE(HAVE_BROKEN_PIPE_BUF, 1, [Define if the system reports an invalid PIPE_BUF value.]) ;;
+esac
 
 
 case $ac_sys_system in