git: 504ac101ba28 - stable/13 - bsdinstall: allow an install script to access packages on the DVD

The branch stable/13 has been updated by asomers:

URL: https://cgit.FreeBSD.org/src/commit/?id=504ac101ba2848d79bce3cd3011fea0438b881e2

commit 504ac101ba2848d79bce3cd3011fea0438b881e2
Author:     Alan Somers <asomers@FreeBSD.org>
AuthorDate: 2022-05-26 21:39:20 +0000
Commit:     Alan Somers <asomers@FreeBSD.org>
CommitDate: 2022-07-24 15:39:58 +0000

    bsdinstall: allow an install script to access packages on the DVD
    
    If installing from the DVD, mount its packages in the chroot at
    /dist/packages.  That way they'll be accessible to an install script.
    
    MFC after:      2 weeks
    Sponsored by:   Axcient
    Reviewed by:    gjb
    Differential Revision: https://reviews.freebsd.org/D35330
    
    (cherry picked from commit 6a02539959cb36c4777f962d3d7ef4a76fbe0c24)
---
 usr.sbin/bsdinstall/scripts/mount  | 6 ++++++
 usr.sbin/bsdinstall/scripts/umount | 7 +++++++
 2 files changed, 13 insertions(+)

diff --git a/usr.sbin/bsdinstall/scripts/mount b/usr.sbin/bsdinstall/scripts/mount
index c7bc1aa5387d..244f11fa215d 100755
--- a/usr.sbin/bsdinstall/scripts/mount
+++ b/usr.sbin/bsdinstall/scripts/mount
@@ -53,3 +53,9 @@ done
 # User might want a shell and require devfs, so mount it
 mkdir $BSDINSTALL_CHROOT/dev 2>/dev/null
 mount -t devfs devfs $BSDINSTALL_CHROOT/dev
+
+# If installing from the DVD, mount packages where they'll be accessible
+if [ -d /packages ]; then
+	mkdir -p $BSDINSTALL_CHROOT/dist/packages
+	mount -t nullfs /packages $BSDINSTALL_CHROOT/dist/packages
+fi
diff --git a/usr.sbin/bsdinstall/scripts/umount b/usr.sbin/bsdinstall/scripts/umount
index 3c33eff7e105..a5d96ffffd32 100755
--- a/usr.sbin/bsdinstall/scripts/umount
+++ b/usr.sbin/bsdinstall/scripts/umount
@@ -26,6 +26,13 @@
 #
 # $FreeBSD$
 
+# If we mounted the DVD packages, unmount them
+if [ -d $BSDINSTALL_CHROOT/dist/packages ]; then
+	umount $BSDINSTALL_CHROOT/dist/packages
+	rmdir $BSDINSTALL_CHROOT/dist/packages
+	rmdir $BSDINSTALL_CHROOT/dist
+fi
+
 TMP_FSTAB=${TMPDIR:-"/tmp"}/bsdinstall-tmp-fstab
 
 cat $PATH_FSTAB | awk -v BSDINSTALL_CHROOT=$BSDINSTALL_CHROOT '{