python3: handle negative errno on Haiku.

also enable _BSD_SOURCE for openpty declaration.

dev-lang/python/patches/python3-3.6.1.patchset

@@ -1,4 +1,4 @@
-From 174b88cd6fbb388545efb2e1218d13eb254defa8 Mon Sep 17 00:00:00 2001
+From 4f5d1b027f1e5b1bba2155aec103cec7233f9d7c Mon Sep 17 00:00:00 2001
 From: Jerome Duval <jerome.duval@gmail.com>
 Date: Thu, 10 Apr 2014 16:03:33 +0000
 Subject: initial Haiku patch
@@ -536,5 +536,43 @@ index f04bf22..718c03a 100644
                  if (self.compiler.find_library_file(lib_dirs, 'nsl')):
                      libs = ['nsl']
 -- 
-2.10.2
+2.11.0
+
+
+From 7133afd2665e636cd11daadbaa672f1a45ed031e Mon Sep 17 00:00:00 2001
+From: Jerome Duval <jerome.duval@gmail.com>
+Date: Sun, 16 Apr 2017 10:05:42 +0200
+Subject: fix for negative errnos
+
+
+diff --git a/Lib/subprocess.py b/Lib/subprocess.py
+index 822ddb4..5334f2d 100644
+--- a/Lib/subprocess.py
++++ b/Lib/subprocess.py
+@@ -1312,6 +1312,8 @@ class Popen(object):
+                 err_msg = err_msg.decode(errors="surrogatepass")
+                 if issubclass(child_exception_type, OSError) and hex_errno:
+                     errno_num = int(hex_errno, 16)
++                    if sys.platform.startswith('haiku'):
++                        errno_num = -errno_num;
+                     child_exec_never_called = (err_msg == "noexec")
+                     if child_exec_never_called:
+                         err_msg = ""
+diff --git a/Modules/_posixsubprocess.c b/Modules/_posixsubprocess.c
+index 5007a39..625c507 100644
+--- a/Modules/_posixsubprocess.c
++++ b/Modules/_posixsubprocess.c
+@@ -521,6 +521,10 @@ error:
+         char *cur;
+         _Py_write_noraise(errpipe_write, "OSError:", 8);
+         cur = hex_errno + sizeof(hex_errno);
++#ifdef __HAIKU__
++        if (saved_errno < 0)
++            saved_errno = -saved_errno;
++#endif
+         while (saved_errno != 0 && cur != hex_errno) {
+             *--cur = Py_hexdigits[saved_errno % 16];
+             saved_errno /= 16;
+-- 
+2.11.0