diff -r a88310d86455 Lib/argparse.py
--- a/Lib/argparse.py	Sun Apr 14 19:22:47 2013 +0200
+++ b/Lib/argparse.py	Mon Apr 15 23:41:40 2013 -0700
@@ -1903,6 +1903,19 @@
             selected_pattern = arg_strings_pattern[start_index:]
             arg_counts = match_partial(positionals, selected_pattern)
 
+            #print([[x[0].dest,x[1]] for x in zip(positionals, arg_counts)])
+            # if arg_count==0 and nargs '*' ('?'as well) make it tentative?
+            # or lop off the last match if count is 0 and there's an 'O' in
+            # remaining pattern
+            # e.g.  'AOAA',[1,0],[null,'*']
+            if 'O' in arg_strings_pattern[start_index:]:
+                # if there is an optional after this, remove
+                # 'empty' positionals from the current match
+                while len(arg_counts)>1 and arg_counts[-1]==0:
+                    print(arg_counts, arg_strings_pattern)
+                    arg_counts = arg_counts[:-1]
+                    print([[x[0].dest,x[1]] for x in zip(positionals, arg_counts)])
+
             # slice off the appropriate arg strings for each Positional
             # and add the Positional and its args to the list
             for action, arg_count in zip(positionals, arg_counts):
diff -r a88310d86455 Lib/test/test_argparse.py
--- a/Lib/test/test_argparse.py	Sun Apr 14 19:22:47 2013 +0200
+++ b/Lib/test/test_argparse.py	Mon Apr 15 23:41:40 2013 -0700
@@ -1254,6 +1254,76 @@
         ('X Y --foo', NS(x='X', y=['Y', '--foo'], z=None)),
     ]
 
+class TestOptionalsBetween2PositionalsZeroOrMore(ParserTestCase):
+    """Tests optionals within positionals, '*' 2nd positional
+    2nd positional is not consumed by the 1st argument set"""
+
+    argument_signatures = [Sig('cmd'),
+                           Sig('-f', '--foo'),
+                           Sig('rest',nargs='*')]
+    failures = ['',  # the following arguments are required: cmd, rest
+                'cmd 1 -f1 2', # unrecognized arguments: 2
+                'cmd 1 --foo 1 2',
+                # optional cannot split arguments for 'rest'
+                ]
+    successes = [
+        ('-f1 cmd 1 2', NS(cmd='cmd', foo='1', rest=['1', '2'])),
+        ('cmd -f1 1 2', NS(cmd='cmd', foo='1', rest=['1', '2'])),
+        ('cmd 1 2 --foo 1', NS(cmd='cmd', foo='1', rest=['1', '2'])),
+        ('cmd --foo 1 1 2',NS(cmd='cmd', foo='1', rest=['1', '2']))
+    ]
+
+class TestOptionalsBetween2PositionalsOptional(ParserTestCase):
+    """Tests optionals within positionals, '?' 2nd positional
+    2nd positional is not consumed by the 1st argument set"""
+
+    argument_signatures = [
+        Sig('cmd'),
+        Sig('-f', '--foo'),
+        Sig('rest',nargs='?')
+    ]
+    failures = []
+    successes = [
+        ('-f1 cmd 1', NS(cmd='cmd', foo='1', rest='1')),
+        ('cmd -f1 1', NS(cmd='cmd', foo='1', rest='1')),
+    ]
+
+class TestOptionalsBetween3PositionalsZeroOrMore(ParserTestCase):
+    """Tests optionals within positionals, '*' 2nd positional
+    2 positionals that might not be consumed by the 1st argument"""
+
+    argument_signatures = [
+        Sig('cmd'),
+        Sig('-f', '--foo'),
+        Sig('resta',nargs='?'),
+        Sig('restb',nargs='*')
+    ]
+    failures = ['cmd 1 2 -f1 3']
+    successes = [
+        ('-f1 cmd 1 2 3', NS(cmd='cmd', foo='1', resta='1', restb=['2', '3'])),
+        ('cmd -f1 1 2 3', NS(cmd='cmd', foo='1', resta='1', restb=['2', '3'])),
+        ('cmd 1 -f1 2 3', NS(cmd='cmd', foo='1', resta='1', restb=['2', '3'])),
+        ('cmd 1 2 3 -f1', NS(cmd='cmd', foo='1', resta='1', restb=['2', '3'])),
+    ]
+
+class TestOptionalsBetween3PositionalsOptional(ParserTestCase):
+    """Tests optionals within positionals, '?' 2nd positional
+    2 positionals that might not be consumed by the 1st argument set"""
+
+    argument_signatures = [
+        Sig('cmd'),
+        Sig('-f', '--foo'),
+        Sig('resta', nargs='?'),
+        Sig('restb', nargs='?')
+    ]
+    failures = []
+    successes = [
+        ('-f1 cmd 1 2', NS(cmd='cmd', foo='1', resta='1', restb='2')),
+        ('cmd -f1 1 2', NS(cmd='cmd', foo='1', resta='1', restb='2')),
+        ('cmd 1 -f1 2', NS(cmd='cmd', foo='1', resta='1', restb='2')),
+        ('cmd 1 2 -f1', NS(cmd='cmd', foo='1', resta='1', restb='2')),
+    ]
+
 
 class TestOptionLike(ParserTestCase):
     """Tests options that may or may not be arguments"""