astropy/astropy — pull request #2794 by embray (2014-09-12 19:45:17+00:00)
Title: fits.writeto writes a corrupt file if the file name ends .gz

@embray -- if you can point me to file where writeto is implemented I can put together a PR to fix it by checking for a name that ends in ``.gz`` and raises an error (unless the desired behavior is to write a gzipped file in that case).

I think this is the real problem I was trying to report in #2779