#9862: On AIX PIPE_BUF is broken. Make it 512.

Patch by Sébastien Sablé.

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.
 

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
 

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