Comment 13 for bug 217654

As discussed with Jonathan Thomas it isn't exactly clear if empty path lines are actually considered wrong.

The Desktop Entry Specification as per http://standards.freedesktop.org/desktop-entry-spec/desktop-entry-spec-1.1.html says the following about the value of keys which require a string:
> Values of type string may contain all ASCII characters except for control characters.
Unlike
> Values of type numeric must be a valid floating point number as recognized by the %f specifier for scanf in the C locale.
which clearly states that the key value _must_ be a valid floating point number.

String _may_ contain ASCII chars, but _may_ as well not do that. Numeric must include a valid floating point number, no content at all isn't meeting the requirements.

desktop-file-validate does also support this interpretation
> kate.desktop: warning: value "" for key "Path" in group "Desktop Entry" does not look like an absolute path
I assume if an empty value was actually breaking the standard compatibility it would use an error: instead of a warning:

Then again this might as well just be a bug in desktop-file-validate, so Jonathan is going to (or already did) get in contact with the responsible people at fd.o to get a clear definition about this.
Depending on the outcome either GNOME needs to fix it's desktop file parser, or KDE needs to get rid of all the empty keys and desktop-file-validate should be fixed to output an error for empty keys.