PDFBOX-5660: optimize, as suggested by Valery Bokov; closes #239

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/trunk@1928151 13f79535-47bb-0310-9956-ffa450edef68

Author: THausherr

pdfbox/src/main/java/org/apache/pdfbox/pdmodel/common/PDStream.java

@@ -199,12 +199,16 @@ public COSInputStream createInputStream(DecodeOptions options) throws IOExceptio
      */
     public InputStream createInputStream(List<String> stopFilters) throws IOException
     {
+        if (stopFilters == null)
+        {
+            stopFilters = Collections.emptyList();
+        }
         InputStream is = stream.createRawInputStream();
         List<Filter> someFilters = new ArrayList<>();
         List<COSName> filters = getFilters();
         for (COSName nextFilter : filters)
         {
-            if (stopFilters != null && stopFilters.contains(nextFilter.getName()))
+            if (stopFilters.contains(nextFilter.getName()))
             {
                 break;
             }