fixes #1286

app/logical/post_sets/post.rb

@@ -69,6 +69,10 @@ module PostSets
       tag_string =~ /\*/
     end
 
+    def is_empty_search?
+      posts.count == 0
+    end
+
     def current_page
       [page.to_i, 1].max
     end

app/presenters/post_set_presenters/post.rb

@@ -9,7 +9,9 @@ module PostSetPresenters
     end
 
     def related_tags
-      if post_set.is_pattern_search?
+      if post_set.is_empty_search?
+        suggested_tags
+      elsif post_set.is_pattern_search?
         pattern_tags
       elsif post_set.is_tag_subscription?
         post_set.tag_subscription_tags
@@ -39,6 +41,12 @@ module PostSetPresenters
       Tag.name_matches(post_set.tag_string).all(:select => "name", :limit => Danbooru.config.tag_query_limit, :order => "post_count DESC").map(&:name)
     end
 
+    def suggested_tags
+      if post_set.tag_string.length >= 3
+        Tag.name_matches("*#{post_set.tag_string}*").where("post_count > 0").all(:select => "name", :limit => Danbooru.config.tag_query_limit, :order => "post_count DESC").map(&:name)
+      end
+    end
+
     def related_tags_for_group
       RelatedTagCalculator.calculate_from_sample_to_array(post_set.tag_string).map(&:first)
     end