Issue #3276072: UpdateReleaseValidator doesn't handle legacy version numbers

automatic_updates_extensions/src/Validator/UpdateReleaseValidator.php

@@ -33,13 +33,12 @@ class UpdateReleaseValidator implements EventSubscriberInterface {
     $messages = [];
     foreach (['production', 'dev'] as $package_type) {
       foreach ($all_versions[$package_type] as $package_name => $sematic_version) {
-        $is_missing_version = FALSE;
-        $legacy_version = NULL;
         $package_parts = explode('/', $package_name);
         $project_name = $package_parts[1];
         // If the version isn't in the list of installable releases, then it
         // isn't secure and supported and the user should receive an error.
         $releases = (new ProjectInfo($project_name))->getInstallableReleases();
+        $is_missing_version = FALSE;
         if (empty($releases)) {
           $is_missing_version = TRUE;
         }
@@ -47,10 +46,14 @@ class UpdateReleaseValidator implements EventSubscriberInterface {
           $legacy_version = LegacyVersionUtility::convertToLegacyVersion($sematic_version);
           if ($legacy_version) {
             if (!array_key_exists($legacy_version, $releases)) {
+              // If we cannot find the version using semantic or legacy then the
+              // version is missing.
               $is_missing_version = TRUE;
             }
           }
           else {
+            // If we cannot convert the semantic version into a legacy version
+            // then the version is missing.
             $is_missing_version = TRUE;
           }
         }