Fix retrieval of image and form resources in PdfResources

DEVSIX-1399

Author: yulian-gaponenko

kernel/src/main/java/com/itextpdf/kernel/pdf/PdfResources.java

@@ -136,8 +136,8 @@ public PdfName addImage(PdfStream image) {
     }
 
     public PdfImageXObject getImage(PdfName name) {
-        PdfStream image = getResource(PdfName.Image).getAsStream(name);
-        return image != null ? new PdfImageXObject(image) : null;
+        PdfStream image = getResource(PdfName.XObject).getAsStream(name);
+        return image != null && PdfName.Image.equals(image.getAsName(PdfName.Subtype)) ? new PdfImageXObject(image) : null;
     }
 
     /**
@@ -178,8 +178,8 @@ public PdfName addForm(PdfFormXObject form, PdfName name) {
     }
 
     public PdfFormXObject getForm(PdfName name) {
-        PdfStream form = getResource(PdfName.Form).getAsStream(name);
-        return form != null ? new PdfFormXObject(form) : null;
+        PdfStream form = getResource(PdfName.XObject).getAsStream(name);
+        return form != null && PdfName.Form.equals(form.getAsName(PdfName.Subtype)) ? new PdfFormXObject(form) : null;
     }
 
     /**

kernel/src/test/java/com/itextpdf/kernel/pdf/PdfImageXObjectTest.java

@@ -54,16 +54,16 @@ public class PdfImageXObjectTest extends ExtendedITextTest {
 
     private static final String sourceFolder = "./src/test/resources/com/itextpdf/kernel/parser/PdfImageXObjectTest/";
 
-    private void testFile(String filename, int page, String objectid) throws Exception{
+    private void testFile(String filename, int page, String objectid) throws Exception {
         PdfDocument pdfDocument = new PdfDocument(new PdfReader(sourceFolder + filename));
-        try{
+        try {
             PdfResources resources = pdfDocument.getPage(page).getResources();
-            PdfDictionary xobjets = resources.getResource(PdfName.XObject);
-            PdfObject obj = xobjets.get(new PdfName(objectid));
+            PdfDictionary xobjects = resources.getResource(PdfName.XObject);
+            PdfObject obj = xobjects.get(new PdfName(objectid));
             if (obj == null) {
-                throw new IllegalArgumentException("Reference " + objectid + " not found - Available keys are " + xobjets.keySet());
+                throw new IllegalArgumentException("Reference " + objectid + " not found - Available keys are " + xobjects.keySet());
             }
-            PdfImageXObject img = new PdfImageXObject((PdfStream)(obj.isIndirectReference() ? ((PdfIndirectReference)obj).getRefersTo() : obj));
+            PdfImageXObject img = new PdfImageXObject((PdfStream) (obj.isIndirectReference() ? ((PdfIndirectReference) obj).getRefersTo() : obj));
             byte[] result = img.getImageBytes(true);
             Assert.assertNotNull(result);
             int zeroCount = 0;