plone/Products.MimetypesRegistry — pull request #1 by cguardia (2012-07-11 17:36:51+00:00)
Title: The python source code guessing line just makes no sense.

Why position 20? It also needs a space or words like 'important' will match. It would be better to just remove the line.

When using things like field.set() to set a text value, which for example is done by transmogrifier and other import products, the guessing can create hard to analyze situations.