tiles to mbtiles fetching

[andrea antonello]

Following several user comments I tried to do a test on a WMS I knew I
had already tiles in the db.

My workflow:

- DISABLE WIFI
- set the wms mapurl backed on mbtiles db
- open the map and go to the place where I know I had tiles

* THE TILES ARE THERE

- then I ENABLE WIFI and move around a bit, having the initial area
outside the view
- tiles are downloaded and visualized as the should

- at some point I DISABLE WIFI again

* instantly some of the border tiles disappear

- I pan slowly to the first location and notice that not all tiles it
had downloaded are where they should
- then I go back to the first location

* ALL THE TILES ARE MISSING


It looks there is something going wrong in the inserting and fetching
from the mbtiles db.

Can anyone please try out my workflow and see if the same happens?

Thanks,
Andrea