SF bug/patch #1433877: string parameter to ioctl not null terminated

The new char-array used in ioctl calls wasn't explicitly NUL-terminated;
quite probably the cause for the test_pty failures on Solaris that we
circumvented earlier. (I wasn't able to reproduce it with this patch, but it
has been somewhat elusive to start with.)
diff --git a/Lib/test/test_pty.py b/Lib/test/test_pty.py
index 99e01b6..7b1f460 100644
--- a/Lib/test/test_pty.py
+++ b/Lib/test/test_pty.py
@@ -4,13 +4,6 @@
 TEST_STRING_1 = "I wish to buy a fish license.\n"
 TEST_STRING_2 = "For my pet fish, Eric.\n"
 
-# Solaris (at least 2.9 and 2.10) seem to have a fickle isatty(). The first
-# test below, testing the result of os.openpty() for tty-ness, sometimes
-# (but not always) fails. The second isatty test, in the sub-process, always
-# works. Allow that fickle first test to fail on these platforms, since it
-# doesn't actually affect functionality.
-fickle_isatty = ["sunos5"]
-
 if verbose:
     def debug(msg):
         print msg
@@ -54,7 +47,7 @@
         # " An optional feature could not be imported " ... ?
         raise TestSkipped, "Pseudo-terminals (seemingly) not functional."
 
-    if not os.isatty(slave_fd) and sys.platform not in fickle_isatty:
+    if not os.isatty(slave_fd):
         raise TestFailed, "slave_fd is not a tty"
 
     debug("Writing to slave_fd")