UBUNTU: [Packaging] reconstruct -- automatically reconstruct against base tag

BugLink: http://bugs.launchpad.net/bugs/1555543Signed-off-by: Andy Whitcroft <apw@canonical.com>

debian/rules.d/1-maintainer.mk

 # The following targets are for the maintainer only! do not run if you don't
 # know what they do.
 
-.PHONY: printenv updateconfigs printchanges insertchanges startnewrelease diffupstream help updateportsconfigs editportsconfigs
+.PHONY: printenv updateconfigs printchanges insertchanges startnewrelease diffupstream help updateportsconfigs editportsconfigs autoreconstruct
 
 help:
 	@echo "These are the targets in addition to the normal $(DEBIAN) ones:"
@@ -104,6 +104,9 @@ printchanges:
 insertchanges:
 	@perl -w -f $(DROOT)/scripts/misc/insert-changes.pl $(DROOT) $(DEBIAN) 
 
+autoreconstruct:
+	$(DROOT)/scripts/misc/gen-auto-reconstruct $(release) >$(DEBIAN)/reconstruct
+
 diffupstream:
 	@git diff-tree -p refs/remotes/linux-2.6/master..HEAD $(shell ls | grep -vE '^(ubuntu|$(DEBIAN)|\.git.*)')
 

debian/scripts/misc/gen-auto-reconstruct

+#!/bin/bash
+
+if [ "$#" -ne 1 ]; then
+	echo "Usage: $0 <orig tag>|<base release>" 1>&2
+	exit 1
+fi
+tag="$1"
+
+case "$tag" in
+v*)	;;
+*)	tag="v${tag%.*}" ;;
+esac
+
+# Validate the tag.
+count=$( git tag -l "$tag" | wc -l )
+if [ "$count" != 1 ]; then
+	echo "$0: $tag: tag invalid" 1>&2
+	exit 1
+fi
+
+#git ls-tree -r --full-tree HEAD | grep ^120 | \
+#while read mode type blobid name
+
+# Identify all new symlinks since the proffered tag.
+echo "# Recreate any symlinks created since the orig."
+git diff "$tag.." --raw | awk '(/^:000000 120000/ && $5 == "A") { print $NF }' | \
+while read name
+do
+	link=$( readlink "$name" )
+
+	echo "[ ! -L '$name' ] && ln -sf '$link' '$name'"
+done
+
+# Identify all removed files since the proffered tag.
+echo "# Remove any files deleted from the orig."
+git diff "$tag.." --raw | awk '(/^:/ && $5 == "D") { print $NF }' | \
+while read name
+do
+	echo "rm -f '$name'"
+done
+
+# All done, make sure this does not complete in error.
+echo "exit 0"