Merge part of the trunk changes into the p3yk branch. This merges from 43030

(branch-creation time) up to 43067. 43068 and 43069 contain a little
swapping action between re.py and sre.py, and this mightily confuses svn
merge, so later changes are going in separately.

This merge should break no additional tests.

The last-merged revision is going in a 'last_merge' property on '.' (the
branch directory.) Arbitrarily chosen, really; if there's a BCP for this, I
couldn't find it, but we can easily change it afterwards ;)

Lib/encodings/unicode_internal.py

@@ -17,6 +17,14 @@ class Codec(codecs.Codec):
     encode = codecs.unicode_internal_encode
     decode = codecs.unicode_internal_decode
 
+class IncrementalEncoder(codecs.IncrementalEncoder):
+    def encode(self, input, final=False):
+        return codecs.unicode_internal_encode(input, self.errors)[0]
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    def decode(self, input, final=False):
+        return codecs.unicode_internal_decode(input, self.errors)[0]
+
 class StreamWriter(Codec,codecs.StreamWriter):
     pass
 
@@ -26,5 +34,12 @@ class StreamReader(Codec,codecs.StreamReader):
 ### encodings module API
 
 def getregentry():
-
-    return (Codec.encode,Codec.decode,StreamReader,StreamWriter)
+    return codecs.CodecInfo(
+        name='unicode-internal',
+        encode=Codec.encode,
+        decode=Codec.decode,
+        incrementalencoder=IncrementalEncoder,
+        incrementaldecoder=IncrementalDecoder,
+        streamwriter=StreamWriter,
+        streamreader=StreamReader,
+    )