diff -r 514cb18945aa Lib/argparse.py
--- a/Lib/argparse.py	Fri Jul 12 20:17:00 2013 -0400
+++ b/Lib/argparse.py	Sun Jul 14 18:55:59 2013 +0800
@@ -311,7 +311,7 @@
 
             # build full usage string
             format = self._format_actions_usage
-            action_usage = format(optionals + positionals, groups)
+            (action_usage, __) = format(optionals + positionals, groups)
             usage = ' '.join([s for s in [prog, action_usage] if s])
 
             # wrap the usage parts if it's too long
@@ -320,10 +320,8 @@
 
                 # break usage into wrappable parts
                 part_regexp = r'\(.*?\)+|\[.*?\]+|\S+'
-                opt_usage = format(optionals, groups)
-                pos_usage = format(positionals, groups)
-                opt_parts = _re.findall(part_regexp, opt_usage)
-                pos_parts = _re.findall(part_regexp, pos_usage)
+                (opt_usage, opt_parts) = format(optionals, groups)
+                (pos_usage, pos_parts) = format(positionals, groups)
                 assert ' '.join(opt_parts) == opt_usage
                 assert ' '.join(pos_parts) == pos_usage
 
@@ -460,6 +458,30 @@
 
         # join all the action items with spaces
         text = ' '.join([item for item in parts if item is not None])
+        arg_parts = []
+        pairs = {'[': ']', '(': ')'}
+        opening_pairs = ('[', '(')
+        closing_pairs = (']', ')')
+        inner = False
+        block = []
+        opening = None
+        # Converting ['[-h]', '(', '--klmno X', '|', '--pqrst X', ')'] to
+        # ['[-h]', '(--klmno X | --pqrst X)']
+        for part in parts:
+            if part is not None:
+                if part in opening_pairs:
+                    opening = part
+                    block.append(part)
+                elif opening:
+                    if part == '|':
+                        part = ' | '
+                    block.append(part)
+                    if part in closing_pairs and part == pairs[opening]:
+                        arg_parts.append(''.join(block))
+                        block = []
+                        opening = None
+                else:
+                    arg_parts.append(part)
 
         # clean up separators for mutually exclusive groups
         open = r'[\[(]'
@@ -471,7 +493,7 @@
         text = text.strip()
 
         # return the text
-        return text
+        return (text, arg_parts)
 
     def _format_text(self, text):
         if '%(prog)' in text:
diff -r 514cb18945aa Lib/test/test_argparse.py
--- a/Lib/test/test_argparse.py	Fri Jul 12 20:17:00 2013 -0400
+++ b/Lib/test/test_argparse.py	Sun Jul 14 18:55:59 2013 +0800
@@ -4118,6 +4118,46 @@
     version = ''
 
 
+class TestHelpMetavarArgumentsInnerBracketSplitLines(HelpTestCase):
+    """"""
+
+    def custom_type(string):
+        return string
+
+    parser_signature = Sig(prog='PROG')
+    long_a = 'a' * 60
+    long_d = 'd' * 60
+    argument_signatures = [Sig('--a', metavar=long_a),
+                           Sig('--b', metavar='[innerpart]outerpart'),
+                           Sig('--c'),
+                           Sig('d', metavar=long_d),
+                           Sig('e', metavar='[innerpart2]outerpart2'),
+                           Sig('f'),
+                           ]
+    argument_group_signatures = []
+    usage = '''\
+       usage: PROG [-h]
+                   [--a {0}]
+                   [--b [innerpart]outerpart] [--c C]
+                   {1}
+                   [innerpart2]outerpart2 f
+       '''.format(long_a, long_d)
+    help = usage + '''\
+
+       positional arguments:
+         {0}
+         [innerpart2]outerpart2
+         f
+
+       optional arguments:
+         -h, --help            show this help message and exit
+         --a {1}
+         --b [innerpart]outerpart
+         --c C
+       '''.format(long_d, long_a)
+    version = ''
+
+
 # =====================================
 # Optional/Positional constructor tests
 # =====================================