Added support of PdfIndirectObject for coordinates in /Rect, /BBox

openpdf/src/main/java/com/lowagie/text/pdf/PdfStamperImp.java

@@ -979,8 +979,8 @@ void flatFields() {
 
                     if (bboxRaw != null && rectRaw != null) {
                         transformNeeded = true;
-                        PdfRectangle bbox = new PdfRectangle(bboxRaw);
-                        PdfRectangle rect = new PdfRectangle(rectRaw);
+                        PdfRectangle bbox = new PdfRectangle(PdfReader.getNormalizedRectangle(bboxRaw));
+                        PdfRectangle rect = new PdfRectangle(PdfReader.getNormalizedRectangle(rectRaw));
 
                         float rectWidth = rect.width();
                         float rectHeight = rect.height();

openpdf/src/test/java/com/lowagie/text/pdf/PdfFormFlatteningTest.java

@@ -5,6 +5,10 @@
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
@@ -127,4 +131,38 @@ void testFlattenTextfieldsWithRotationAndMatrix() throws IOException {
             pdfReader.close();
         }
     }
+
+    @Test
+    void testFlattenFieldsWithPdfIndirectObjectInRect() throws IOException {
+        final Path targetFilePath = Paths.get("target/indirect_object_in_rectangle-flattened.pdf");
+        try (InputStream resource = getClass().getResourceAsStream(
+                "/flattening/indirect_object_in_rectangle.pdf")) {
+            Assertions.assertNotNull(resource, "File could not be found!");
+            OutputStream fos = Files.newOutputStream(targetFilePath);
+
+            PdfReader pdfReader = new PdfReader(resource);
+            PdfStamper stamper = new PdfStamper(pdfReader, fos);
+
+            stamper.getAcroFields().setGenerateAppearances(true);
+            stamper.setFormFlattening(true);
+
+            pdfReader.close();
+            stamper.close();
+        }
+        //Verify no form fields left (the correct shape is difficult to verify...)
+        try (InputStream resource = Files.newInputStream(targetFilePath)) {
+
+            Assertions.assertNotNull(resource, "File could not be found!");
+            PdfReader pdfReader = new PdfReader(resource);
+
+            PdfDictionary acroForm = (PdfDictionary) PdfReader.getPdfObjectRelease(
+                    pdfReader.getCatalog().get(PdfName.ACROFORM));
+            Assertions.assertTrue(acroForm == null
+                    || acroForm.getAsArray(PdfName.FIELDS) == null
+                    || acroForm.getAsArray(PdfName.FIELDS).isEmpty());
+
+            pdfReader.close();
+        }
+    }
+
 }