Fix bug with long prog= values.

2 files changed, 155 insertions, 40 deletions

diff --git a/argparse.py b/argparse.py
index 0f407e7..75a9043 100644
--- a/argparse.py
+++ b/argparse.py
@@ -327,7 +327,7 @@ class HelpFormatter(object):
 
         # if optionals and positionals are available, calculate usage
         elif usage is None:
-            usage = '%(prog)s' % dict(prog=self._prog)
+            prog = '%(prog)s' % dict(prog=self._prog)
 
             # split optionals from positionals
             optionals = []
@@ -338,44 +338,69 @@ class HelpFormatter(object):
                 else:
                     positionals.append(action)
 
-            # determine width of "usage: PROG" and width of text
-            prefix_width = len(prefix) + len(usage) + 1
-            prefix_indent = self._current_indent + prefix_width
-            text_width = self._width - self._current_indent
-
-            # put them on one line if they're short enough
+            # build full usage string
             format = self._format_actions_usage
             action_usage = format(optionals + positionals, groups)
-            if prefix_width + len(action_usage) + 1 < text_width:
-                usage = '%s %s' % (usage, action_usage)
+            usage = ' '.join([s for s in [prog, action_usage] if s])
 
-            # if they're long, wrap optionals and positionals individually
-            else:
-                optional_usage = format(optionals, groups)
-                positional_usage = format(positionals, groups)
-                indent = ' ' * prefix_indent
-
-                # usage is made of PROG, optionals and positionals
-                parts = [usage, ' ']
-
-                # options always get added right after PROG
-                if optional_usage:
-                    parts.append(_textwrap.fill(
-                        optional_usage, text_width,
-                        initial_indent=indent,
-                        subsequent_indent=indent).lstrip())
-
-                # if there were options, put arguments on the next line
-                # otherwise, start them right after PROG
-                if positional_usage:
-                    part = _textwrap.fill(
-                        positional_usage, text_width,
-                        initial_indent=indent,
-                        subsequent_indent=indent).lstrip()
-                    if optional_usage:
-                        part = '\n' + indent + part
-                    parts.append(part)
-                usage = ''.join(parts)
+            # wrap the usage parts if it's too long
+            text_width = self._width - self._current_indent
+            if len(prefix) + len(usage) > text_width:
+
+                # 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)
+                assert ' '.join(opt_parts) == opt_usage
+                assert ' '.join(pos_parts) == pos_usage
+
+                # helper for wrapping lines
+                def get_lines(parts, indent, prefix=None):
+                    lines = []
+                    line = []
+                    if prefix is not None:
+                        line_len = len(prefix) - 1
+                    else:
+                        line_len = len(indent) - 1
+                    for part in parts:
+                        if line_len + 1 + len(part) > text_width:
+                            lines.append(indent + ' '.join(line))
+                            line = []
+                            line_len = len(indent) - 1
+                        line.append(part)
+                        line_len += len(part) + 1
+                    if line:
+                        lines.append(indent + ' '.join(line))
+                    if prefix is not None:
+                        lines[0] = lines[0][len(indent):]
+                    return lines
+
+                # if prog is short, follow it with optionals or positionals
+                if len(prefix) + len(prog) <= 0.75 * text_width:
+                    indent = ' ' * (len(prefix) + len(prog) + 1)
+                    if opt_parts:
+                        lines = get_lines([prog] + opt_parts, indent, prefix)
+                        lines.extend(get_lines(pos_parts, indent))
+                    elif pos_parts:
+                        lines = get_lines([prog] + pos_parts, indent, prefix)
+                    else:
+                        lines = [prog]
+
+                # if prog is long, put it on its own line
+                else:
+                    indent = ' ' * len(prefix)
+                    parts = opt_parts + pos_parts
+                    lines = get_lines(parts, indent)
+                    if len(lines) > 1:
+                        lines = []
+                        lines.extend(get_lines(opt_parts, indent))
+                        lines.extend(get_lines(pos_parts, indent))
+                    lines = [prog] + lines
+
+                # join lines into usage
+                usage = '\n'.join(lines)
 
         # prefix with 'usage:'
         return '%s%s\n\n' % (prefix, usage)
diff --git a/test/test_argparse.py b/test/test_argparse.py
index 57de0c4..447a4dd 100644
--- a/test/test_argparse.py
+++ b/test/test_argparse.py
@@ -2095,12 +2095,12 @@ class TestMutuallyExclusiveLong(MEMixin, TestCase):
     ]
 
     usage_when_not_required = '''\
-    usage: PROG [-h] [--abcde ABCDE] [--fghij FGHIJ] [--klmno KLMNO | --pqrst
-                PQRST]
+    usage: PROG [-h] [--abcde ABCDE] [--fghij FGHIJ]
+                [--klmno KLMNO | --pqrst PQRST]
     '''
     usage_when_required = '''\
-    usage: PROG [-h] [--abcde ABCDE] [--fghij FGHIJ] (--klmno KLMNO | --pqrst
-                PQRST)
+    usage: PROG [-h] [--abcde ABCDE] [--fghij FGHIJ]
+                (--klmno KLMNO | --pqrst PQRST)
     '''
     help = '''\
 
@@ -2855,6 +2855,96 @@ class TestHelpOnlyUserGroups(HelpTestCase):
     version = ''
 
 
+class TestHelpUsageLongProg(HelpTestCase):
+    """Test usage messages where the prog is long"""
+
+    parser_signature = Sig(prog='P' * 60)
+    argument_signatures = [
+        Sig('-w', metavar='W'),
+        Sig('-x', metavar='X'),
+        Sig('a'),
+        Sig('b'),
+    ]
+    argument_group_signatures = []
+    usage = '''\
+        usage: PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP
+               [-h] [-w W] [-x X] a b
+        '''
+    help = usage + '''\
+
+        positional arguments:
+          a
+          b
+
+        optional arguments:
+          -h, --help  show this help message and exit
+          -w W
+          -x X
+        '''
+    version = ''
+
+
+class TestHelpUsageLongProgOptionsWrap(HelpTestCase):
+    """Test usage messages where the prog is long and the optionals wrap"""
+
+    parser_signature = Sig(prog='P' * 60)
+    argument_signatures = [
+        Sig('-w', metavar='W' * 25),
+        Sig('-x', metavar='X' * 25),
+        Sig('-y', metavar='Y' * 25),
+        Sig('-z', metavar='Z' * 25),
+        Sig('a'),
+        Sig('b'),
+    ]
+    argument_group_signatures = []
+    usage = '''\
+        usage: PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP
+               [-h] [-w WWWWWWWWWWWWWWWWWWWWWWWWW] \
+[-x XXXXXXXXXXXXXXXXXXXXXXXXX]
+               [-y YYYYYYYYYYYYYYYYYYYYYYYYY] [-z ZZZZZZZZZZZZZZZZZZZZZZZZZ]
+               a b
+        '''
+    help = usage + '''\
+
+        positional arguments:
+          a
+          b
+
+        optional arguments:
+          -h, --help            show this help message and exit
+          -w WWWWWWWWWWWWWWWWWWWWWWWWW
+          -x XXXXXXXXXXXXXXXXXXXXXXXXX
+          -y YYYYYYYYYYYYYYYYYYYYYYYYY
+          -z ZZZZZZZZZZZZZZZZZZZZZZZZZ
+        '''
+    version = ''
+
+
+class TestHelpUsageLongProgPositionalsWrap(HelpTestCase):
+    """Test usage messages where the prog is long and the positionals wrap"""
+
+    parser_signature = Sig(prog='P' * 60, add_help=False)
+    argument_signatures = [
+        Sig('a' * 25),
+        Sig('b' * 25),
+        Sig('c' * 25),
+    ]
+    argument_group_signatures = []
+    usage = '''\
+        usage: PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP
+               aaaaaaaaaaaaaaaaaaaaaaaaa bbbbbbbbbbbbbbbbbbbbbbbbb
+               ccccccccccccccccccccccccc
+        '''
+    help = usage + '''\
+
+        positional arguments:
+          aaaaaaaaaaaaaaaaaaaaaaaaa
+          bbbbbbbbbbbbbbbbbbbbbbbbb
+          ccccccccccccccccccccccccc
+        '''
+    version = ''
+
+
 class TestHelpUsageOptionalsWrap(HelpTestCase):
     """Test usage messages where the optionals wrap"""