Android allows other apps to access protected content of an app without requesting the
necessary permission when the app returns an Intent with FLAG_GRANT_READ_URI_PERMISSION.
This regularly happens as a result of ACTION_GET_CONTENT, i.e. what we use to pick content
to be attached to a message. Accessing that content only works while the receiving activity
is running. Afterwards accessing the content throws a SecurityException because of the
missing permission.
This commit changes K-9 Mail's behavior to copy the content to a temporary file in K-9's
cache directory while the activity is still running.
Fixes issue 4847, 5821
This also fixes bugs related to the fact that K-9 Mail didn't save a copy of attached content
in the message database.
Fixes issue 1187, 3330, 4930
Previously the app crashed when upgrading the database failed. Now we
reset the database version and run the upgrade code again (recreating
all tables).
This requires another database schema change. With this change messages
at the root of a thread reference themselves in the 'threads' table,
i.e. 'root' contains the value of 'id' for these messages. It makes
selecting all messages in a thread much simpler.
Database updates can be surprisingly slow. This lead to slow updates of
the user interface which in turn made working with K-9 Mail not as fun
as it should be. This commit hopefully changes that.
The commit that introduced those notifications also introduced a rather
... interesting design pattern: The CertificateValidationException
notified the user of its pure existance - it's no longer a 'message'
only, but defines policy. As this is more than unusual, replace this
pattern by the MessagingController treating
CertificateValidationException specially when accessing remote folders.
Also make clear which account failed when constructing the notification.
With this fix, a CertPathValidatorException or CertificateException will
create a "Certificate error: Check your server settings" notification
in the status bar. When the user clicks on the notification, they are
taken to the appropriate server settings screen where they can review their
settings and can accept a different server certificate.
This changes the interface to MessagingController and the way flags are
updated in the database. Now messages aren't changed one by one but in
batches of 500. This should give better performance, but breaks the
unread and flagged count. I'm not very sad about this, because now we
can move towards only displaying the number of unread/flagged messages
in the local database.
