[openwrt/openwrt] base-files: sysupgrade: do not rely on opkg to list changed conffiles

[LEDE Commits]

neoraider pushed a commit to openwrt/openwrt.git, branch lede-17.01:
https://git.lede-project.org/17c0362178caf837680a4631b8d0de94e5393448

commit 17c0362178caf837680a4631b8d0de94e5393448
Author: Matthias Schiffer <mschiffer at universe-factory.net>
AuthorDate: Tue Mar 6 08:25:32 2018 +0100

    base-files: sysupgrade: do not rely on opkg to list changed conffiles
    
    Many packages use the opkg conffiles field to list configuration files that
    are to be retained on upgrades. Make this work on systems without opkg.
    
    Signed-off-by: Matthias Schiffer <mschiffer at universe-factory.net>
---
 package/base-files/Makefile              |  2 +-
 package/base-files/files/sbin/sysupgrade | 21 ++++++++++++++++++++-
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/package/base-files/Makefile b/package/base-files/Makefile
index 3fcf20a..38d72fd 100644
--- a/package/base-files/Makefile
+++ b/package/base-files/Makefile
@@ -11,7 +11,7 @@ include $(INCLUDE_DIR)/kernel.mk
 include $(INCLUDE_DIR)/version.mk
 
 PKG_NAME:=base-files
-PKG_RELEASE:=173.3
+PKG_RELEASE:=173.4
 PKG_FLAGS:=nonshared
 
 PKG_FILE_DEPENDS:=$(PLATFORM_DIR)/ $(GENERIC_PLATFORM_DIR)/base-files/
diff --git a/package/base-files/files/sbin/sysupgrade b/package/base-files/files/sbin/sysupgrade
index c095ca8..71c7faa 100755
--- a/package/base-files/files/sbin/sysupgrade
+++ b/package/base-files/files/sbin/sysupgrade
@@ -101,12 +101,31 @@ EOF
 # prevent messages from clobbering the tarball when using stdout
 [ "$CONF_BACKUP" = "-" ] && export VERBOSE=0
 
+
+list_conffiles() {
+	awk '
+		BEGIN { conffiles = 0 }
+		/^Conffiles:/ { conffiles = 1; next }
+		!/^ / { conffiles = 0; next }
+		conffiles == 1 { print }
+	' /usr/lib/opkg/status
+}
+
+list_changed_conffiles() {
+	# Cannot handle spaces in filenames - but opkg cannot either...
+	list_conffiles | while read file csum; do
+		[ -r "$file" ] || continue
+
+		echo "${csum}  ${file}" | sha256sum -sc - || echo "$file"
+	done
+}
+
 add_uci_conffiles() {
 	local file="$1"
 	( find $(sed -ne '/^[[:space:]]*$/d; /^#/d; p' \
 		/etc/sysupgrade.conf /lib/upgrade/keep.d/* 2>/dev/null) \
 		-type f -o -type l 2>/dev/null;
-	  opkg list-changed-conffiles ) | sort -u > "$file"
+	  list_changed_conffiles ) | sort -u > "$file"
 	return 0
 }