Daemon fails to start up when processing removable media if there are duplicate keys in media and media_attic tables

[James Henstridge]

From a report from Mitchell Reese on the ubuntu-phone list, it seems we can hit terminate on startup when processing removable media.

The log extract was:

    Mediascanner service starting at 2015-10-02 6:31:12.

    terminate called after throwing an instance of 'std::runtime_error'
      what(): UNIQUE constraint failed: media_attic.id

This is almost definitely from the MediaStorePrivate::archiveItems() method, indicating that some of the items being moved to the attic were assigned the same primary key ID as other items we'd previously moved to the attic.

Ignoring the ID field when copying between the two tables would probably be the best solution.

As a work around for anyone who encounters this before we roll out a fix, deleting the media index should make the problem go away:

    stop mediascanner-2.0
    rm ~/.cache/mediascanner-2.0/mediastore.db
    start mediascanner-2.0

[MankyGitt (dnadruff)]

Note, the workaround does not fix the problem. Removing the .cache content (in fact I removed all of .cache also in testing, makes no difference. On user login, the same error is presented.

I will retest in due course without any peripherals attached to see if this is a factor. Currently testing with the following:
Dell XPS15 (9530) - which worked flawlessly with 14.04LTS aside from poor support for UltraHD displays.

1. HDMI external monitor
2. USB receiver for Wireless Mouse + KB
2. USB 2.0 external HDD

I have observed the same crashes without some or all of these items.
Again, not an issue with 14.04 - this seems to be a new issue.

[MankyGitt (dnadruff)]

Just noticed a new patch including media-scanner for 15.04. I'll test and advise.