Backup/Restore SMS/MMS via ADB on a non-rooted device?

Is there any way to backup/restore SMS and MMS messages using ADB, when the device is not rooted?

• adb pull won't work here, as the corresponding database (/data/data/com.android.providers.telephony/databases/mmssms.db) cannot be read by ADB if it's not running in insecure (root) mode


• adb shell "cat /data/data/com.android.providers.telephony/databases/mmssms.db > /sdcard/mmssms.db doesn't work either without root access


• adb backup for some reason doesn't cover this database on the device I've checked with (empty backup – just the 41 bytes of the backup header in the resulting file)

I especially wonder why adb backup doesn't cover this. If it's for "privacy reasons", then the same should apply to the contacts database – which clearly is backed up.

References:

So: Any solution on a non-rooted device? Note that I'm NOT asking for an app-based solution. I'm fully aware there are several apps available for this. I specifically want a "shell based solution", to be used via ADB.