mimeapps.list not applying as expected

[Hibou57 (Yannick Duchêne)]

First, I noticed editing preferred application to open a file of a given type, could not be edited any‑more from the file property dialogue box. I wanted to check if something was wrong with the `mimeapps.list` file. I found nothing wrong, except perhaps, its owning directory, which is `$HOME/.local/share/applications/` instead which is said to be a deprecated location, according to [1], so I wanted to move to `$HOME/.config/`, the recommended location after [1], but then noticed it's even worse, as it seems to be totally ignored when located there.

So there are at least two issues: preferred application cannot be any‑more edited using the GUI (file's property dialogue box) and so `mimeapps.list` must be edited manually, and then, the location of this file does not seems to conform to the Freedesktop standard (works only at a deprecated location and does not work at the recommended location).

[1]: http://standards.freedesktop.org/mime-apps-spec/mime-apps-spec-1.0.html

Note: I may be wrong stating the bug is in `xdg-utils`, it's a reasonable (to me) guess I made.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: xdg-utils 1.1.0~rc1-2ubuntu7.1
ProcVersionSignature: Ubuntu 3.13.0-68.111-generic 3.13.11-ckt27
Uname: Linux 3.13.0-68-generic i686
ApportVersion: 2.14.1-0ubuntu3.19
Architecture: i386
CurrentDesktop: Unity
Date: Mon Nov 30 22:12:45 2015
InstallationDate: Installed on 2015-01-25 (309 days ago)
InstallationMedia: Ubuntu 12.04.5 LTS "Precise Pangolin" - Release i386 (20140807.1)
PackageArchitecture: all
SourcePackage: xdg-utils
UpgradeStatus: Upgraded to trusty on 2015-04-22 (222 days ago)

[Hibou57 (Yannick Duchêne) (yannick-duchene)]

Additionally, manual editing of `mimeapps.list` does not even always work. For some mime‑type, adding an entry in `[Default Applications]` does not make it the default, but is displayed by the Nautilus file menu, as if it was in `[Added Associations]`.

I've checked there is a single one `mimeapps.list` on my system, so that exclude a conflict between multiple `mimeapps.list`.