Fix sole ruleset selector being treated as

Author: cheese3660

Runtime/SassyPatching/Execution/SassyTextPatcher.cs

@@ -71,13 +71,21 @@ private void RecursivelyFindRuleSet(Selector selector)
                 {
                     RecursivelyFindRuleSet(intersectionSelector.Selectors[0]);
                 }
-            } else if (selector is ChildSelector childSelector)
+            } 
+            else if (selector is ChildSelector childSelector)
             {
                 RecursivelyFindRuleSet(childSelector.Parent);
             }
+            else if (selector is RulesetSelector rulesetSelector)
+            {
+                if (!Universe.RuleSets.TryGetValue(rulesetSelector.RulesetName, out var ruleSet))
+                {
+                    throw new InterpreterException(rulesetSelector.Coordinate,
+                        $"Ruleset {rulesetSelector.RulesetName} does not exist!");
+                }
+                RuleSet = ruleSet;
+            }
         }
-        
-        
 
         public string OriginalGuid { get; }
         public string PriorityString { get; }
@@ -111,4 +119,4 @@ public bool TryPatchBegin(string patchType, string name, string data, out ISelec
             return _rootSelectionBlock.ExecuteFresh(_environmentSnapshot, selectable);
         }
     }
-}
+}