install/59095: sysinst: "entire disk" layout vs. pre-existing partitions

[martin%NetBSD.org@localhost]

>Number:         59095
>Category:       install
>Synopsis:       sysinst: "entire disk" layout vs. pre-existing partitions
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    install-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Feb 23 15:50:00 +0000 2025
>Originator:     Martin Husemann
>Release:        NetBSD 10.99.12
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD big-apple.aprisoft.de 10.99.12 NetBSD 10.99.12 (POWERMAC_G5.MP) #130: Tue Feb 18 11:28:23 CET 2025 martin%seven-days-to-the-wolves.aprisoft.de@localhost:/work/src/sys/arch/macppc/compile/POWERMAC_G5.MP macppc
Architecture: powerpc
Machine: macppc
>Description:

Originally reported by Jared:

Install to a disk with existing GPT and existing partitions, do
not explicitly kill the GPT when selecting the partitioning type,
then tell sysinst to use the "entire disk" layout and default partition
sizes.

Sysinst will (of course) not delete foreign partitions by itself but in
this combination no real "entire disk" layout is possible, so the
result is an unexpected mix.

>How-To-Repeat:
s/a

>Fix:
Prompt the user for permission to delete the foreign partitions when
"entire disk" has been selected.