Fixes some notices in the resource reommendation patch that just landed, a=chris

diff --git a/src/controllers/components/SocialComponent.php b/src/controllers/components/SocialComponent.php
index 8c14a4986..7e0306d1f 100644
--- a/src/controllers/components/SocialComponent.php
+++ b/src/controllers/components/SocialComponent.php
@@ -3920,8 +3920,8 @@ EOD;
                 $group_model->getGroupPageResourceUrls($group_id,
                     $data['PAGE_ID'], $sub_path,
                     needs_descriptions_format:
-                    $data["HEAD"]['update_description']);
-            $thumb_folder = $data['RESOURCES_INFO']['thumb_folder'];
+                    $data["HEAD"]['update_description'] ?? "");
+            $thumb_folder = $data['RESOURCES_INFO']['thumb_folder'] ?? "";
             if (!empty($thumb_folder)) {
                 $fp = fopen(self::RECOMMENDATION_FILE, "a");
                 fwrite($fp, $group_id . "###" . $data['PAGE_ID'] . "###" .
diff --git a/src/library/media_jobs/RecommendationJob.php b/src/library/media_jobs/RecommendationJob.php
index f18332dac..6f316e9b7 100644
--- a/src/library/media_jobs/RecommendationJob.php
+++ b/src/library/media_jobs/RecommendationJob.php
@@ -218,6 +218,7 @@ class RecommendationJob extends MediaJob
             " GROUP_RESOURCE_RECOMMENDATION GROUP BY GROUP_ID," .
             " PAGE_ID, RESOURCE_PATH, RESOURCE_ID ORDER BY TOTAL_SCORE DESC";
         $results = $db->execute($sql);
+        $popular_recommendations[C\RESOURCE_RECOMMENDATION] = [];
         while ($row = $db->fetchArray($results)) {
             $popular_recommendations[C\RESOURCE_RECOMMENDATION][] = $row;
         }
@@ -789,8 +790,11 @@ class RecommendationJob extends MediaJob
      */
     public function getWikiResourceDescriptions()
     {
-        $thumb_folders = explode("\n",
-            file_get_contents(self::RECOMMENDATION_FILE));
+        $thumb_folders = [];
+        if (file_exists(self::RECOMMENDATION_FILE)) {
+            $thumb_folders = explode("\n",
+                file_get_contents(self::RECOMMENDATION_FILE));
+        }
         $thumb_folders = array_unique($thumb_folders);
         $descriptions = [];
         $resource_metadata = [];
diff --git a/tests/ManyUserExperiment.php b/tests/ManyUserExperiment.php
index 5fad12999..5fcb5b604 100644
--- a/tests/ManyUserExperiment.php
+++ b/tests/ManyUserExperiment.php
@@ -95,7 +95,7 @@ for ($i = 0; $i < C\ME_NUM_GROUPS; $i++) {
 // add lots of users to groups (everyone belongs to at least group 1)
 for ($i = 0; $i < C\ME_NUM_GROUPS; $i++) {
     $user_id = $user_ids[$i];
-    for ($j = 1; $j < ($i/10)+1; $j++) {
+    for ($j = 1; $j < ($i/10) + 1; $j++) {
         if ($j != $i) {//by above user $i is owner (and so in) group $i
             echo "Adding User $i (user id $user_id) to ".
                 "Group $j (group id {$group_ids[$j]})\n";