[Cython] Bug: comprehensions clear current exception

[Andrew Svetlov]

I have an issue in aiohttp library:
https://github.com/KeepSafe/aiohttp/issues/410

The source of problem is: when I execute the following code

body = ', '.join("'{}': {!r}".format(k, v) for k, v in self.items())

in except block Cython clears exception.

Changing from comprehension to regular iteration works well:

lst = []
for k, v in self._items:
    lst.append("'{}': {!r}".format(k, v))
body = ', '.join(lst)

In pyre Python both versions don't clear current exception.

I think it's a Cython bug.

-- 
Thanks,
Andrew Svetlov