display: use stdout for column width (#70199)

stdout may differ from stdin so it should be used to determine the column
width, especially since it is the target file descriptor.

changelogs/fragments/display-stdout-column-width.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - Ansible output now uses stdout to determine column width instead of stdin

lib/ansible/utils/display.py

@@ -530,8 +530,8 @@ class Display(with_metaclass(Singleton, object)):
         return encoding
 
     def _set_column_width(self):
-        if os.isatty(0):
-            tty_size = unpack('HHHH', fcntl.ioctl(0, TIOCGWINSZ, pack('HHHH', 0, 0, 0, 0)))[1]
+        if os.isatty(1):
+            tty_size = unpack('HHHH', fcntl.ioctl(1, TIOCGWINSZ, pack('HHHH', 0, 0, 0, 0)))[1]
         else:
             tty_size = 0
         self.columns = max(79, tty_size - 1)