Merged revisions 79077,79137,79304-79305 via svnmerge from

svn+ssh://pythondev@svn.python.org/sandbox/trunk/2to3/lib2to3

........
  r79077 | benjamin.peterson | 2010-03-18 18:05:29 -0500 (Thu, 18 Mar 2010) | 1 line

  port detect_encoding improvements from py3k
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  r79137 | benjamin.peterson | 2010-03-20 11:12:53 -0500 (Sat, 20 Mar 2010) | 1 line

  add a fixer for setting sys.exitfunc #2356
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  r79304 | benjamin.peterson | 2010-03-22 17:20:22 -0500 (Mon, 22 Mar 2010) | 1 line

  fix test_parser when it's run in a path with spaces #7666
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  r79305 | benjamin.peterson | 2010-03-22 17:27:07 -0500 (Mon, 22 Mar 2010) | 1 line

  normalize whitespace
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1 files changed, 10 insertions, 9 deletions

diff --git a/Lib/lib2to3/pgen2/tokenize.py b/Lib/lib2to3/pgen2/tokenize.py
index e0f45f9..521e7b7 100644
--- a/Lib/lib2to3/pgen2/tokenize.py
+++ b/Lib/lib2to3/pgen2/tokenize.py
@@ -253,14 +253,16 @@ def detect_encoding(readline):
     in.
 
     It detects the encoding from the presence of a utf-8 bom or an encoding
-    cookie as specified in pep-0263. If both a bom and a cookie are present,
-    but disagree, a SyntaxError will be raised. If the encoding cookie is an
-    invalid charset, raise a SyntaxError.
+    cookie as specified in pep-0263. If both a bom and a cookie are present, but
+    disagree, a SyntaxError will be raised. If the encoding cookie is an invalid
+    charset, raise a SyntaxError.  Note that if a utf-8 bom is found,
+    'utf-8-sig' is returned.
 
     If no encoding is specified, then the default of 'utf-8' will be returned.
     """
     bom_found = False
     encoding = None
+    default = 'utf-8'
     def read_or_stop():
         try:
             return readline()
@@ -287,17 +289,16 @@ def detect_encoding(readline):
             if codec.name != 'utf-8':
                 # This behaviour mimics the Python interpreter
                 raise SyntaxError('encoding problem: utf-8')
-            else:
-                # Allow it to be properly encoded and decoded.
-                encoding = 'utf-8-sig'
+            encoding += '-sig'
         return encoding
 
     first = read_or_stop()
     if first.startswith(BOM_UTF8):
         bom_found = True
         first = first[3:]
+        default = 'utf-8-sig'
     if not first:
-        return 'utf-8', []
+        return default, []
 
     encoding = find_cookie(first)
     if encoding:
@@ -305,13 +306,13 @@ def detect_encoding(readline):
 
     second = read_or_stop()
     if not second:
-        return 'utf-8', [first]
+        return default, [first]
 
     encoding = find_cookie(second)
     if encoding:
         return encoding, [first, second]
 
-    return 'utf-8', [first, second]
+    return default, [first, second]
 
 def untokenize(iterable):
     """Transform tokens back into Python source code.