PDFBOX-6018: add test for orphan popup annotations

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/trunk@1926333 13f79535-47bb-0310-9956-ffa450edef68

Author: THausherr

pdfbox/src/test/java/org/apache/pdfbox/multipdf/PDFMergerUtilityTest.java

@@ -1437,6 +1437,37 @@ void testSplitWithPgEntryAtTheTop() throws IOException
         }
     }
 
+    /**
+     * PDFBOX-6018: Test split a PDF with popup annotations that are not in the annotations list.
+     * Verify that after splitting, they still link back to their markup annotation and these to the
+     * page.
+     *
+     * @throws IOException
+     */
+    @Test
+    void testSplitWithOrphanPopupAnnotation() throws IOException
+    {
+        try (PDDocument doc = Loader.loadPDF(new File(SRCDIR, "PDFBOX-6018-099267-p9-OrphanPopups.pdf")))
+        {
+            Splitter splitter = new Splitter();
+            List<PDDocument> splitResult = splitter.split(doc);
+            assertEquals(1, splitResult.size());
+            try (PDDocument dstDoc = splitResult.get(0))
+            {
+                assertEquals(1, dstDoc.getNumberOfPages());
+                PDPage page = dstDoc.getPage(0);
+                List<PDAnnotation> annotations = page.getAnnotations();
+                assertEquals(2, annotations.size());
+                PDAnnotationText ann0 = (PDAnnotationText) annotations.get(0);
+                PDAnnotationText ann1 = (PDAnnotationText) annotations.get(1);
+                assertEquals(page, ann0.getPage());
+                assertEquals(page, ann1.getPage());
+                assertEquals(ann0, ann0.getPopup().getParent());
+                assertEquals(ann1, ann1.getPopup().getParent());
+            }            
+        }
+    }
+
     /**
      * PDFBOX-5939: merge a file with an outline that has itself as a parent without producing a
      * stack overflow.