I recently received a bug report about the free space calculation in gnome-vfs-obexftp. At the moment, the code exposes a single free space value for the OBEX connection. However, some phones expose multiple volumes via the virtual file system presented via OBEX.
It turns out my own phone does this, which was useful for testing. The Nokia 6230 can store things on the phone’s memory (named DEV in the OBEX capabilities list), or the Multimedia Card (named MMC). So the fix would be to show the DEV free space when browsing folders on DEV and the MMC free space when browsing folders on MMC.
Doing a bit of investigation, I found that the information I wanted was in the folder listings:
<?xml version="1.0"?> <!DOCTYPE folder-listing SYSTEM "obex-folder-listing.dtd" [ <!ATTLIST folder mem-type CDATA #IMPLIED> ]> <folder-listing version="1.0"> <folder name="Memory card" user-perm="RW" mem-type="MMC"/> <folder name="Images" created="19800101T000008" user-perm="R" mem-type="DEV"/> ... </folder-listing>
I took a look through the OBEX specification, and this mem-type wasn’t defined. So it looked like a Nokia extension. Doing a quick search, the closest I came to a describing it was US patent application #20060095537.
So Nokia is effectively trying to patent an XML attribute. I’d seen a lot of bad patents, but this seemed particularly weak. The patent application even comes with a useful diagram explaining the invention:
As far as I can tell, using the information returned from the phone wouldn’t be covered by the patent (if it gets issued, that is). So it should be fine to use the information to calculate free space more accurately.