From 31e53c35e81dbc93ac1226f29fb5c5955817b74a Mon Sep 17 00:00:00 2001
From: Zac Medico <zmedico@gentoo.org>
Date: Wed, 26 Sep 2007 20:01:23 +0000
Subject: [PATCH] Set non-blocking mode on the pty master file descriptor while
 the slave file descriptor is still held open since otherwise the fcntl call
 can fail on FreeBSD (the child process might have already exited and closed
 the slave file descriptor so we have to keep it open in order to avoid
 FreeBSD potentially generating an EAGAIN exception). This appoach is cleaner
 than triggering the exception and being forced to handle it somehow.

svn path=/main/trunk/; revision=7835
---
 pym/portage/__init__.py | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/pym/portage/__init__.py b/pym/portage/__init__.py
index 7a2fa0855..24b246be7 100644
--- a/pym/portage/__init__.py
+++ b/pym/portage/__init__.py
@@ -2442,6 +2442,16 @@ def spawn(mystring, mysettings, debug=0, free=0, droppriv=0, sesandbox=0, fakero
 			writemsg("openpty failed: '%s'\n" % str(e), noiselevel=1)
 			del e
 			master_fd, slave_fd = os.pipe()
+
+		# We must set non-blocking mode before we close the slave_fd
+		# since otherwise the fcntl call can fail on FreeBSD (the child
+		# process might have already exited and closed slave_fd so we
+		# have to keep it open in order to avoid FreeBSD potentially
+		# generating an EAGAIN exception).
+		import fcntl
+		fcntl.fcntl(master_fd, fcntl.F_SETFL,
+			fcntl.fcntl(master_fd, fcntl.F_GETFL) | os.O_NONBLOCK)
+
 		fd_pipes.setdefault(0, sys.stdin.fileno())
 		fd_pipes_orig = fd_pipes.copy()
 		if got_pty and os.isatty(fd_pipes_orig[1]):
@@ -2488,7 +2498,7 @@ def spawn(mystring, mysettings, debug=0, free=0, droppriv=0, sesandbox=0, fakero
 	try:
 		mypids.extend(spawn_func(mystring, env=env, **keywords))
 	finally:
-		if slave_fd:
+		if logfile:
 			os.close(slave_fd)
 		if sesandbox:
 			selinux.setexec(None)
@@ -2503,26 +2513,14 @@ def spawn(mystring, mysettings, debug=0, free=0, droppriv=0, sesandbox=0, fakero
 		iwtd = [master_file]
 		owtd = []
 		ewtd = []
-		import array, fcntl, select
-		fd_flags = {}
-		for f in iwtd:
-			fd_flags[f] = fcntl.fcntl(f.fileno(), fcntl.F_GETFL)
+		import array, select
 		buffsize = 65536
 		eof = False
-		# Use non-blocking mode to prevent read
-		# calls from blocking indefinitely.
-		try:
-			fcntl.fcntl(master_file.fileno(), fcntl.F_SETFL,
-				fd_flags[master_file] | os.O_NONBLOCK)
-		except EnvironmentError, e:
-			if e.errno != errno.EAGAIN:
-				raise
-			del e
-			# The EAGAIN error signals eof on FreeBSD.
-			eof = True
 		while not eof:
 			events = select.select(iwtd, owtd, ewtd)
 			for f in events[0]:
+				# Use non-blocking mode to prevent read
+				# calls from blocking indefinitely.
 				buf = array.array('B')
 				try:
 					buf.fromfile(f, buffsize)
-- 
2.26.2