Only call _test_pty_eof() on Linux, since it seems to hang on most other

kernels. This should fix the hang reported on FreeBSD here:
http://archives.gentoo.org/gentoo-alt/msg_d81c5e8c6dd6849312ecb048feb41c5b.xml
(trunk r14606)

svn path=/main/branches/2.1.7/; revision=14636

2 files changed, 25 insertions, 7 deletions

diff --git a/pym/portage/__init__.py b/pym/portage/__init__.py
index 08d8f415..54d45dab 100644
--- a/pym/portage/__init__.py
+++ b/pym/portage/__init__.py
@@ -3777,6 +3777,15 @@ class config(object):
 		keys = __iter__
 		items = iteritems
 
+def _can_test_pty_eof():
+	"""
+	The _test_pty_eof() function seems to hang on most
+	kernels other than Linux.
+	@rtype: bool
+	@returns: True if _test_pty_eof() won't hang, False otherwise.
+	"""
+	return platform.system() in ("Linux",)
+
 def _test_pty_eof():
 	"""
 	Returns True if this issues is fixed for the currently
@@ -3861,9 +3870,13 @@ def _test_pty_eof():
 
 	return test_string == ''.join(data)
 
-# In some cases, openpty can be slow when it fails. Therefore,
-# stop trying to use it after the first failure.
-if platform.system() not in ["FreeBSD", "Linux"]:
+# If _test_pty_eof() can't be used for runtime detection of
+# http://bugs.python.org/issue5380, openpty can't safely be used
+# unless we can guarantee that the current version of python has
+# been fixed (affects all current versions of python3). When
+# this issue is fixed in python3, we can add another sys.hexversion
+# conditional to enable openpty support in the fixed versions.
+if sys.hexversion >= 0x3000000 and not _can_test_pty_eof():
 	# Disable the use of openpty on Solaris as it seems Python's openpty
 	# implementation doesn't play nice on Solaris with Portage's
 	# behaviour causing hangs/deadlocks.
@@ -3880,6 +3893,10 @@ else:
 	_disable_openpty = False
 _tested_pty = False
 
+if not _can_test_pty_eof():
+	# Skip _test_pty_eof() on systems where it hangs.
+	_tested_pty = True
+
 def _create_pty_or_pipe(copy_term_size=None):
 	"""
 	Try to create a pty and if then fails then create a normal
diff --git a/pym/portage/tests/ebuild/test_pty_eof.py b/pym/portage/tests/ebuild/test_pty_eof.py
index 0dd1e850..31a5df4a 100644
--- a/pym/portage/tests/ebuild/test_pty_eof.py
+++ b/pym/portage/tests/ebuild/test_pty_eof.py
@@ -13,7 +13,8 @@ class PtyEofTestCase(TestCase):
 		# Since it might not be fixed, mark as todo.
 		self.todo = True
 		# The result is only valid if openpty does not raise EnvironmentError.
-		try:
-			self.assertEqual(portage._test_pty_eof(), True)
-		except EnvironmentError:
-			pass
+		if portage._can_test_pty_eof():
+			try:
+				self.assertEqual(portage._test_pty_eof(), True)
+			except EnvironmentError:
+				pass