georg.brandl> Patch #2 looks innocent enough to me, 
georg.brandl> and is clearly an improvement.

Ok, issue fixed by r88140 (+r88141):

Issue #10955: zipimport uses ASCII encoding instead of cp497 to decode
filenames, at bootstrap, if the codec registry is not ready yet. It is
still possible to have non-ASCII filenames using the Unicode flag
(UTF-8 encoding) for all file entries in the ZIP file.

Oh, by the way, using ASCII at bootstrap is not a regression of Python 3.2: Python 3.1 used the wrong encoding (UTF-8) to decode filenames encoded to cp437. Raise a UnicodeDecodeError is better than decoding with the wrong encoding.

> For 3.3, we might want to consider implementing cp437 in C, ...

Since, I don't like this solution, I will not open a new issue for that. Feel free to open a new issue if you consider that we need that in Python 3.3.