Comment 111 for bug 1265192

On Tue, Oct 14, 2014 at 03:48:30PM -0000, Chris Bainbridge wrote:
> @Colin Will your changes fix the problems with multiple drives?

I'll certainly check what happens with multiple drives and try to make
sure it's reasonable. (Needless to say, the tests are somewhat
time-consuming.) Adding a confirmation dialog provides an extra safety
net, although does require recognising which device is which so it's not
perfect.

> - a two disk setup of first disk with (undetected) EFI Windows 8 and
> second disk with Ubuntu is handled as a 'single OS Ubuntu upgrade', and
> when the user clicks to upgrade, the Windows disk is wiped.

This should not be a problem; with my patches the "Erase Ubuntu and
reinstall" option in the single-detected-OS case will really just erase
Ubuntu, not be a stealth "wipe the disk" option.

> - If there are two disks, and os-prober shows no operating systems
> on sda and Ubuntu on sdb, then the Ubiquity "Install" screen will have
> title "Erase Ubuntu 12.04 and reinstall" and will incorrectly select
> drive "sda" (Ubuntu is not on sda).

Similarly, "erase Ubuntu and reinstall" won't wipe a disk any more; it
will remove the partition corresponding to the Ubuntu root file system
and autopartition whatever's left. This is the underlying "replace"
option, and is what "Erase Ubuntu and reinstall" already mapped to in
the case where Ubuntu and some other operating system are detected. I
think it makes a lot of sense to ensure that the same option text always
corresponds to the same underlying implementation.

The "Erase disk and install Ubuntu" option will still send you off to
select which disk to wipe (I believe; as I say, I still need to test
this), but I think that's a lot more forgiveable when it's preceded by
"This will delete all your programs, documents, photos, music, and any
other files in all operating systems". If anything, that overstates the
case on a system with multiple disks. We will in any event no longer be
implying by the structure of the automatic partitioning workflow that
the disk that's selected by default is the one that previously contained
Ubuntu.

> It does say that "4 partitions will be deleted" (another bug, it seems
> to include free space gaps in the partition count)

Indeed, thanks. I have a patch for that in my tree now, pending
testing.

> (Also, there are tests for autopartitioning in tests/test_ubi_partman.py
> - if you are familiar with the test code here it might be useful to add
> some test cases to cover the error cases documented in this bug report
> - multiple partitions and/or drives, os-proper potentially returning
> nothing - so that future code changes will not reintroduce these bugs.)

Yes, my changes make those tests fail right now, so I'll have to update
them in any case.