Fix XMP Exctrator not returning empty optional

CHANGELOG.md

@@ -352,6 +352,7 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 - We fixed an issue where the "Attach file" dialog, in the right-click menu for an entry, started on the working directory instead of the user's main directory. [#4995](https://github.com/JabRef/jabref/issues/4995)
 - We fixed an issue where the JabRef Icon in the macOS launchpad was not displayed correctly [#5003](https://github.com/JabRef/jabref/issues/5003)
 - We fixed an issue where the "Search for unlinked local files" would throw an exception when parsing the content of a PDF-file with missing "series" information [#5128](https://github.com/JabRef/jabref/issues/5128)
+- We fixed an issue where the XMP Importer would incorrectly return an empty default entry when importing pdfs [#6577](https://github.com/JabRef/jabref/issues/6577)
 
 ### Removed
 

src/main/java/org/jabref/logic/xmp/DublinCoreExtractor.java

@@ -61,7 +61,7 @@ private void extractEditor() {
     private void extractAuthor() {
         List<String> creators = dcSchema.getCreators();
         if ((creators != null) && !creators.isEmpty()) {
-            bibEntry.setField(StandardField.AUTHOR, String.join(" and ", creators));
+           bibEntry.setField(StandardField.AUTHOR, String.join(" and ", creators));
         }
     }
 
@@ -242,10 +242,10 @@ public Optional<BibEntry> extractBibtexEntry() {
         this.extractTitle();
         this.extractType();
 
-        if (bibEntry.getType() == null) {
-            bibEntry.setType(BibEntry.DEFAULT_TYPE);
+        // we pass a new BibEntry in the constructor which is never empty as it already consists of "@misc"
+        if (bibEntry.getFieldMap().isEmpty()) {
+            return Optional.empty();
         }
-
         return Optional.of(bibEntry);
     }