[rox-devel] Patch to provide support for application/x-zerosize

[Norm P. <npi...@da...>]

Attached is a patch to provide support in ROX-Filer for the
application/x-zerosize MIME type.

The changes made to the code are mostly just a subset of the changes in a
patch submitted to the xdgmime code base by David Faure.  (See
"xdg/xdgmime: Implement text vs binary fallback; support for
application/x-zerosize" at
http://cgit.freedesktop.org/xdg/xdgmime/commit/?id=5181175d5fdaa3832b0fd094cda0120b1fe92af6
)  My only contributions were to make a small change in the
diritem_restat() function so empty files are no longer assumed to be
text/plain, and to make a change to the xdg_mime_get_mime_type_for_file()
function identical to a change Faure made to the
_xdg_mime_cache_get_mime_type_for_file() function; this fixes an omission
in his patch so that this will still work even if there is no support for
the mime.cache file.

Note that David Faure's patch also adds support for guessing whether a
file is binary or text if no other method has been able to identify the
MIME type.  ROX-Filer has had support for that since 2005 (with a short
vacation from 2007-08-18 to 2008-01-21 when the code had been mistakenly
removed).  I have retained the ROX-Filer code for that support and not
implemented David Faure's related changes.


Related reading:

Some discussion of Faure's patch is available here (although mostly about 
the part of his patch not used in my patch):
"Re: Questions regarding the shared mime spec"
http://old.nabble.com/Questions-regarding-the-shared-mime-spec-td32227868.html#a32563181

Bug report regarding omission in Faure's patch:
"Bug 55120 - application/x-zerosize isn't supported when not using cache."
https://bugs.freedesktop.org/show_bug.cgi?id=55120