Improve version handling to prevent inadvertent downgrades (#226)

* Improve version handling to prevent inadvertent downgrades
* Add verbose output for version checking
* Improved git branch handling for testing
* Stay on current branch unless BRANCHNAME is set
* Add verbose output for in-use check

Author: demonbane

plexupdate-core

@@ -198,6 +198,7 @@ running() {
 		# Get a total count of active media (MediaContainer size), then deduct one for every paused stream.
 		# If all streams are paused, we consider the server to not be active.
 		local mediacount="$(awk -F'"' '/<MediaContainer size="[0-9]+">/ {count+=$2}; /<Player[^>]* state="paused"/ {count--}; END {print count}' <<< "${DATA}")"
+		[ "$VERBOSE" = "yes" ] && printf 'Activity check reports a count of %i, based on return data of:\n%s\n\n' "${mediacount}" "${DATA}" >&2
 		[ $mediacount -gt 0 ] && return 0
 	fi
 
@@ -209,6 +210,53 @@ verifyToken() {
 	wget -qO /dev/null "https://plex.tv/api/resources?X-Plex-Token=${TOKEN}"
 }
 
+isNewerVersion() {
+	# Returns true ONLY if 1 > 2.
+	[ -z "$1" ] && return 1
+	[ -z "$2" ] && return
+	[ "$1" = "$2" ] && return 1
+	if hash dpkg 2>/dev/null; then
+		dpkg --compare-versions "$1" gt "$2"
+	elif sort -V --version &>/dev/null; then
+		[ "$(printf "$1\n$2" | sort -Vr | head -n1)" = "$1" ]
+	else
+		# sort has had -V since at least 2009, so nobody should ever see this
+		warn "Unable to compare version numbers, assuming '$1' is newer."
+	fi
+}
+
+parseVersion() {
+	if [ "${REDHAT}" = "yes" ]; then
+		cut -f2- -d- <<< "$1" | cut -f1-4 -d.
+	else
+		cut -f2 -d_ <<< "$1"
+	fi
+}
+
+getPlexVersion() {
+	if [ "${REDHAT}" != "yes" ]; then
+		dpkg-query --showformat='${Version}' --show plexmediaserver 2>/dev/null
+	elif hash rpm 2>/dev/null; then
+		local rpmtemp
+		if rpmtemp=$(rpm -q plexmediaserver); then
+			parseVersion "$rpmtemp"
+		else
+			return 1
+		fi
+	else
+		error "Unknown OS, exiting."
+		exit 1
+	fi
+}
+
+verboseOutput() {
+	if [ "$VERBOSE" = "yes" ]; then
+		for i in $@; do
+			info "$i=${!i}"
+		done
+	fi
+}
+
 # Shared functions
 
 # SHARED

plexupdate.sh

@@ -228,8 +228,13 @@ if [ "${AUTOUPDATE}" = "yes" ]; then
 	elif ! git diff --quiet; then
 		warn "You have made changes to the plexupdate files, cannot auto update"
 	else
+		if [ -z "${BRANCHNAME}" ]; then
+			BRANCHNAME="$(git symbolic-ref -q --short HEAD)"
+		elif [ "${BRANCHNAME}" != "$(git symbolic-ref -q --short HEAD)" ]; then
+			git checkout "${BRANCHNAME}"
+		fi
 		# Force FETCH_HEAD to point to the correct branch (for older versions of git which don't default to current branch)
-		if git fetch origin ${BRANCHNAME:-master} --quiet && ! git diff --quiet FETCH_HEAD; then
+		if git fetch origin ${BRANCHNAME} --quiet && ! git diff --quiet FETCH_HEAD; then
 			info "Auto-updating..."
 
 			# Use an associative array to store permissions. If you're running bash < 4, the declare will fail and we'll
@@ -385,11 +390,7 @@ RELEASE=$(grep -ioe '"label"[^}]*' <<<"${wgetresults}" | grep -i "\"distro\":\"$
 DOWNLOAD=$(echo ${RELEASE} | grep -m1 -ioe 'https://[^\"]*')
 CHECKSUM=$(echo ${RELEASE} | grep -ioe '\"checksum\"\:\"[^\"]*' | sed 's/\"checksum\"\:\"//')
 
-if [ "$VERBOSE" = "yes" ]; then
-	for i in RELEASE DOWNLOAD CHECKSUM; do
-		info "$i=${!i}"
-	done
-fi
+verboseOutput RELEASE DOWNLOAD CHECKSUM
 
 if [ -z "${DOWNLOAD}" ]; then
 	if [ "$DISTRO" = "ubuntu" -a "$BUILD" = "linux-ubuntu-armv7l" ]; then
@@ -423,30 +424,25 @@ fi
 # By default, try downloading
 SKIP_DOWNLOAD="no"
 
-# Installed version detection
-if [ "${REDHAT}" != "yes" ]; then
-	INSTALLED_VERSION=$(dpkg-query -s plexmediaserver 2>/dev/null | grep -Po 'Version: \K.*')
-else
-	if [ "${AUTOINSTALL}" = "yes" -a "${AUTOSTART}" = "no" ]; then
-		warn "Your distribution may require the use of the AUTOSTART [-s] option for the service to start after the upgrade completes."
-	fi
-	INSTALLED_VERSION=$(rpm -qv plexmediaserver 2>/dev/null)
+INSTALLED_VERSION="$(getPlexVersion)" || warn "Unable to detect installed version, first time?"
+FILE_VERSION="$(parseVersion "${FILENAME}")"
+verboseOutput INSTALLED_VERSION FILE_VERSION
+
+if [ "${REDHAT}" = "yes" -a "${AUTOINSTALL}" = "yes" -a "${AUTOSTART}" = "no" ]; then
+	warn "Your distribution may require the use of the AUTOSTART [-s] option for the service to start after the upgrade completes."
 fi
 
 if [ "${CHECKONLY}" = "yes" ]; then
-	if [ -z "${INSTALLED_VERSION}" ]; then
-		warn "Unable to detect installed version, first time?"
-	elif [[ $FILENAME != *$INSTALLED_VERSION* ]]; then
-		AVAIL="$(echo "${FILENAME}" | sed -nr 's/^[^0-9]+([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+\-[^_]+).*/\1/pg')"
-		info "Your OS reports Plex $INSTALLED_VERSION installed, newer version is available (${AVAIL})"
+	if [ -n "${INSTALLED_VERSION}" ] && isNewerVersion "$FILE_VERSION" "$INSTALLED_VERSION"; then
+		info "Your OS reports Plex $INSTALLED_VERSION installed, newer version is available (${FILE_VERSION})"
 		exit 7
-	else
+	elif [ -n "${INSTALLED_VERSION}" ]; then
 		info "You are running the latest version of Plex (${INSTALLED_VERSION})"
 	fi
 	exit 0
 fi
 
-if [[ $FILENAME == *$INSTALLED_VERSION* ]] && [ "${FORCE}" != "yes" ] && [ ! -z "${INSTALLED_VERSION}" ]; then
+if ! isNewerVersion "$FILE_VERSION" "$INSTALLED_VERSION" && [ "${FORCE}" != "yes" ]; then
 	info "Your OS reports the latest version of Plex ($INSTALLED_VERSION) is already installed. Use -f to force download."
 	exit 0
 fi