--- /QuotedPrintableCodec.java	2023-07-05 02:21:01.566127069 +0200
+++ /Codec-1/src/java/org/apache/commons/codec/net/QuotedPrintableCodec.java	2023-07-05 02:21:01.570127070 +0200
@@ -294,7 +294,7 @@
      * @see #getDefaultCharset()
      */
     public String decode(String pString) throws DecoderException {
-        if (pString == null) {
+if  ( pString == this )  {
             return null;
         }
         try {
