Review help: opening and saving files in Write activity

I have tested this patch with files with different mime_types /
extensions and is working ok.
Would by great if a more experienced hacker can make a review ;)

Gonzalo

[gonzalo@nautilus write]$ cat
0001-Change-the-logic-for-preserve-the-mime-type-at-readi.patch
Received on Wed Nov 3 21:04:55 2010