Only apply YAML preprocessing if the initial parse attempt fails

src/Parse/Yaml.php

@@ -29,12 +29,17 @@ public function parse($contents)
     {
         $yaml = new Parser;
 
-        if (!is_null($this->processor)) {
+        // Only run the preprocessor if parsing fails
+        try {
+            $parsed = $yaml->parse($contents);
+        } catch (\Throwable $throwable) {
+            if (!$this->processor) {
+                throw $throwable;
+            }
             $contents = $this->processor->preprocess($contents);
+            $parsed = $yaml->parse($contents);
         }
 
-        $parsed = $yaml->parse($contents);
-
         if (!is_null($this->processor)) {
             $parsed = $this->processor->process($parsed);
         }