Prevent migration from ownCloud 11 to Nextcloud 12

Signed-off-by: Joas Schilling <coding@schilljs.com>

1 files changed, 16 insertions, 20 deletions

diff --git a/lib/private/Updater.php b/lib/private/Updater.php
index a66d49941cd..3f4e54cf803 100644
--- a/lib/private/Updater.php
+++ b/lib/private/Updater.php
@@ -157,9 +157,9 @@ class Updater extends BasicEmitter {
 	/**
 	 * Return version from which this version is allowed to upgrade from
 	 *
-	 * @return string allowed previous version
+	 * @return array allowed previous versions per vendor
 	 */
-	private function getAllowedPreviousVersion() {
+	private function getAllowedPreviousVersions() {
 		// this should really be a JSON file
 		require \OC::$SERVERROOT . '/version.php';
 		/** @var array $OC_VersionCanBeUpgradedFrom */
@@ -182,26 +182,22 @@ class Updater extends BasicEmitter {
 	 * Whether an upgrade to a specified version is possible
 	 * @param string $oldVersion
 	 * @param string $newVersion
-	 * @param string $allowedPreviousVersion
+	 * @param array $allowedPreviousVersions
 	 * @return bool
 	 */
-	public function isUpgradePossible($oldVersion, $newVersion, $allowedPreviousVersion) {
-		$allowedUpgrade = (version_compare($allowedPreviousVersion, $oldVersion, '<=')
-			&& (version_compare($oldVersion, $newVersion, '<=') || $this->config->getSystemValue('debug', false)));
-
-		if ($allowedUpgrade) {
-			return $allowedUpgrade;
+	public function isUpgradePossible($oldVersion, $newVersion, array $allowedPreviousVersions) {
+		$version = explode('.', $oldVersion);
+		$majorMinor = $version[0] . '.' . $version[1];
+
+		$currentVendor = $this->config->getAppValue('core', 'vendor', '');
+		if ($currentVendor === 'nextcloud') {
+			return isset($allowedPreviousVersions[$currentVendor][$majorMinor])
+				&& (version_compare($oldVersion, $newVersion, '<=') ||
+					$this->config->getSystemValue('debug', false));
 		}
 
-		// Upgrade not allowed, someone switching vendor?
-		if ($this->getVendor() !== $this->config->getAppValue('core', 'vendor', '')) {
-			$oldVersion = explode('.', $oldVersion);
-			$newVersion = explode('.', $newVersion);
-
-			return $oldVersion[0] === $newVersion[0] && $oldVersion[1] === $newVersion[1];
-		}
-
-		return false;
+		// Check if the instance can be migrated
+		return isset($allowedPreviousVersions[$currentVendor][$majorMinor]);
 	}
 
 	/**
@@ -215,8 +211,8 @@ class Updater extends BasicEmitter {
 	 */
 	private function doUpgrade($currentVersion, $installedVersion) {
 		// Stop update if the update is over several major versions
-		$allowedPreviousVersion = $this->getAllowedPreviousVersion();
-		if (!self::isUpgradePossible($installedVersion, $currentVersion, $allowedPreviousVersion)) {
+		$allowedPreviousVersions = $this->getAllowedPreviousVersions();
+		if (!$this->isUpgradePossible($installedVersion, $currentVersion, $allowedPreviousVersions)) {
 			throw new \Exception('Updates between multiple major versions and downgrades are unsupported.');
 		}