Factor out grub-related diversions and use them consistently, so we

don't end up with wrong os-probe output in our grub.cfg.

debian/changelog

@@ -1,3 +1,10 @@
+livecd-rootfs (2.466) UNRELEASED; urgency=medium
+
+  * Factor out grub-related diversions and use them consistently, so we
+    don't end up with wrong os-probe output in our grub.cfg.
+
+ -- Steve Langasek <steve.langasek@ubuntu.com>  Wed, 04 Oct 2017 22:31:40 -0700
+
 livecd-rootfs (2.465) artful; urgency=medium
 
   * Skip installation of kernel headers for all minimal images

live-build/functions

@@ -283,3 +283,32 @@ replace_grub_root_with_label() {
     sed -i -e "s,root=[^ ]\+,root=LABEL=${fs_label}," \
         "$CHROOT_ROOT/boot/grub/grub.cfg"
 }
+
+
+# When running update-grub in a chroot on a build host, we don't want it to
+# probe for disks or probe for other installed OSes.  Extract common
+# diversion wrappers, so this isn't reinvented differently for each image.
+divert_grub() {
+	CHROOT_ROOT="$1"
+
+	chroot "$CHROOT_ROOT" dpkg-divert --local \
+		--rename /usr/sbin/grub-probe
+	chroot "$CHROOT_ROOT" touch /usr/sbin/grub-probe
+	chroot "$CHROOT_ROOT" chmod +x /usr/sbin/grub-probe
+
+	chroot "$CHROOT_ROOT" dpkg-divert --local \
+		--divert /etc/grub.d/30_os-prober.dpkg-divert \
+		--rename /etc/grub.d/30_os-prober
+}
+
+undivert_grub() {
+	CHROOT_ROOT="$1"
+
+	chroot "$CHROOT_ROOT" rm /usr/sbin/grub-probe
+	chroot "$CHROOT_ROOT" dpkg-divert --remove --local \
+		--rename /usr/sbin/grub-probe
+
+	chroot "$CHROOT_ROOT" dpkg-divert --remove --local \
+		--divert /etc/grub.d/30_os-prober.dpkg-divert \
+		--rename /etc/grub.d/30_os-prober
+}

live-build/ubuntu-cpc/hooks/032-disk-image.binary

@@ -125,7 +125,9 @@ if [ "${should_install_grub}" -eq 1 ]; then
 		echo "partuuid found for root device; forcing it in Grub"
 		mkdir -p mountpoint/etc/default/grub.d
 		echo "GRUB_FORCE_PARTUUID=$partuuid" >> mountpoint/etc/default/grub.d/40-force-partuuid
+		divert_grub mountpoint
 		chroot mountpoint update-grub
+		undivert_grub mountpoint
 	fi
 fi
 

live-build/ubuntu-cpc/hooks/033-disk-image-uefi.binary

@@ -110,10 +110,10 @@ install_grub() {
         chroot mountpoint grub-install --target=i386-pc "${loop_device}"
     fi
 
-    chroot mountpoint dpkg-divert --local --rename /etc/grub.d/30_os-prober
+    divert_grub mountpoint
     chroot mountpoint update-grub
     replace_grub_root_with_label mountpoint
-    chroot mountpoint dpkg-divert --remove --local --rename /etc/grub.d/30_os-prober
+    undivert_grub mountpoint
 
     chroot mountpoint apt-get -y clean
 

live-build/ubuntu-cpc/hooks/034-disk-image-ppc64el.binary

@@ -52,10 +52,10 @@ EOF
         --boot-directory=/boot \
         --target=powerpc-ieee1275
 
-    chroot mountpoint dpkg-divert --local --rename /etc/grub.d/30_os-prober
+    divert_grub mountpoint
     chroot mountpoint update-grub
     replace_grub_root_with_label mountpoint
-    chroot mountpoint dpkg-divert --remove --local --rename /etc/grub.d/30_os-prober
+    undivert_grub mountpoint
 
     umount_partition mountpoint
     rmdir mountpoint