Fix CompareTool#compareByCatalog method: add page dictionaries comparison

Author: yulian-gaponenko

kernel/src/main/java/com/itextpdf/kernel/utils/CompareTool.java

@@ -187,6 +187,18 @@ public CompareResult compareByCatalog(PdfDocument outDocument, PdfDocument cmpDo
         Set<PdfName> ignoredCatalogEntries = new LinkedHashSet<>(Arrays.asList(PdfName.Metadata));
         compareDictionariesExtended(outDocument.getCatalog().getPdfObject(), cmpDocument.getCatalog().getPdfObject(),
                 catalogPath, compareResult, ignoredCatalogEntries);
+
+        // Method compareDictionariesExtended eventually calls compareObjects method which doesn't compare page objects.
+        // At least for now compare page dictionaries explicitly here like this.
+        if (outPagesRef.size() != cmpPagesRef.size()) {
+            compareResult.addError(catalogPath, "Documents have different numbers of pages.");
+        }
+        for (int i = 0; i < Math.min(cmpPagesRef.size(), outPagesRef.size()); i++) {
+            ObjectPath currentPath = new ObjectPath(cmpPagesRef.get(i), outPagesRef.get(i));
+            PdfDictionary outPageDict = (PdfDictionary) outPagesRef.get(i).getRefersTo();
+            PdfDictionary cmpPageDict = (PdfDictionary) cmpPagesRef.get(i).getRefersTo();
+            compareDictionariesExtended(outPageDict, cmpPageDict, currentPath, compareResult);
+        }
         return compareResult;
     }
 

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

@@ -296,6 +296,9 @@ private boolean checkParentTree(String outFileName, String cmpFileName) throws I
     	PdfReader cmpReader = new PdfReader(cmpFileName);
     	PdfDocument cmpDocument = new PdfDocument(cmpReader);
     	CompareResult result = new CompareTool().compareByCatalog(outDocument, cmpDocument);
+    	if (!result.isOk()) {
+            System.out.println(result.getReport());
+        }
     	return result.isOk();
     }
 }