commit 701138a380fac06023e5915448af92ba13614cb9
Author: aszlig <aszlig@redmoonstudios.org>
Date:   Thu Feb 11 03:14:07 2016 +0100

    vterm: Fix handling of NUL characters
    
    According to the VT100 programmers manual, the NUL character has to be
    ignored (at least on our side, because we are not a printer):
    
    http://vt100.net/docs/tp83/appendixb.html
    
    According to the bug reporter the VMS console driver inserts NUL
    characters after line feeds and our implementation prints those as "?".
    
    Tested against Python 2.7, 3.2, 3.3, 3.4 and 3.5.
    
    Signed-off-by: aszlig <aszlig@redmoonstudios.org>
    Reported-by: Robert Urban <urban@unix-beratung.de>

diff --git a/urwid/tests/test_vterm.py b/urwid/tests/test_vterm.py
index 59fe166..4dadfcc 100644
--- a/urwid/tests/test_vterm.py
+++ b/urwid/tests/test_vterm.py
@@ -143,6 +143,10 @@ class TermTest(unittest.TestCase):
         self.write('1\n2\n3\n4\e[2;1f\e[2M')
         self.expect('1\n4')
 
+    def test_nul(self):
+        self.write('a\0b')
+        self.expect('ab')
+
     def test_movement(self):
         self.write('\e[10;20H11\e[10;0f\e[20C\e[K')
         self.expect('\n' * 9 + ' ' * 19 + '1')
diff --git a/urwid/vterm.py b/urwid/vterm.py
index cc4eb7f..0f091ea 100644
--- a/urwid/vterm.py
+++ b/urwid/vterm.py
@@ -671,7 +671,7 @@ class TermCanvas(Canvas):
             self.widget.beep()
         elif not dc and char in B("\x18\x1a"): # CAN/SUB
             self.leave_escape()
-        elif not dc and char == B("\x7f"): # DEL
+        elif not dc and char in B("\x00\x7f"): # NUL/DEL
             pass # this is ignored
         elif self.within_escape:
             self.parse_escape(char)