From dd699b62c59d8fdbdf97a219a2a1125b691e5a98 Mon Sep 17 00:00:00 2001
From: Tim Peters <tim.peters@gmail.com>
Date: Wed, 27 Dec 2000 08:05:05 +0000
Subject: [PATCH] Fix for SF bug
 https://sourceforge.net/bugs/?func=detailbug&bug_id=126863&group_id=5470
 "getopt long option handling broken".  Tossed the excruciating logic in
 long_has_args in favor of something obviously correct.

---
 Lib/getopt.py | 43 ++++++++++++++++++++++++++++++-------------
 1 file changed, 30 insertions(+), 13 deletions(-)

diff --git a/Lib/getopt.py b/Lib/getopt.py
index a6ddf44bb05..c93aad179c5 100644
--- a/Lib/getopt.py
+++ b/Lib/getopt.py
@@ -66,7 +66,7 @@ def getopt(args, shortopts, longopts = []):
     else:
         longopts = list(longopts)
     longopts.sort()
-    while args and args[0][:1] == '-' and args[0] != '-':
+    while args and args[0].startswith('-') and args[0] != '-':
         if args[0] == '--':
             args = args[1:]
             break
@@ -80,9 +80,10 @@ def getopt(args, shortopts, longopts = []):
 def do_longs(opts, opt, longopts, args):
     try:
         i = opt.index('=')
-        opt, optarg = opt[:i], opt[i+1:]
     except ValueError:
         optarg = None
+    else:
+        opt, optarg = opt[:i], opt[i+1:]
 
     has_arg, opt = long_has_args(opt, longopts)
     if has_arg:
@@ -98,19 +99,35 @@ def do_longs(opts, opt, longopts, args):
 # Return:
 #   has_arg?
 #   full option name
+# Assumes longopts has been sorted (ASCII order).
 def long_has_args(opt, longopts):
-    optlen = len(opt)
     for i in range(len(longopts)):
-        x, y = longopts[i][:optlen], longopts[i][optlen:]
-        if opt != x:
-            continue
-        if y != '' and y != '=' and i+1 < len(longopts):
-            if opt == longopts[i+1][:optlen]:
-                raise GetoptError('option --%s not a unique prefix' % opt, opt)
-        if longopts[i][-1:] in ('=', ):
-            return 1, longopts[i][:-1]
-        return 0, longopts[i]
-    raise GetoptError('option --%s not recognized' % opt, opt)
+        if longopts[i].startswith(opt):
+            break
+    else:
+        raise GetoptError('option --%s not recognized' % opt, opt)
+    # opt is a prefix of longopts[i]; find j s.t. opt is a prefix of
+    # each possibility in longopts[i:j]
+    j = i+1
+    while j < len(longopts) and longopts[j].startswith(opt):
+        j += 1
+    possibilities = longopts[i:j]
+    # Is there an exact match?
+    if opt in possibilities:
+        return 0, opt
+    elif opt + '=' in possibilities:
+        return 1, opt
+    # No exact match, so better be unique.
+    if len(possibilities) > 1:
+        # XXX since possibilities contains all valid continuations, might be
+        # nice to work them into the error msg
+        raise GetoptError('option --%s not a unique prefix' % opt, opt)
+    assert len(possibilities) == 1
+    unique_match = possibilities[0]
+    has_arg = unique_match.endswith('=')
+    if has_arg:
+        unique_match = unique_match[:-1]
+    return has_arg, unique_match
 
 def do_shorts(opts, optstring, shortopts, args):
     while optstring != '':