Ignore invalid catalog version on document load

Some invalid values in the optional Version field of the Catalog
caused an exception on PDFDocument construction.
It is now ignored and the document is created successfully.

Closes 65.

Author: borislucas-dev

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

@@ -1941,9 +1941,12 @@ protected void open(PdfVersion newPdfVersion) {
                 if (catalog.getPdfObject().containsKey(PdfName.Version)) {
                     // The version of the PDF specification to which the document conforms (for example, 1.4)
                     // if later than the version specified in the file's header
-                    PdfVersion catalogVersion = PdfVersion.fromPdfName(catalog.getPdfObject().getAsName(PdfName.Version));
-                    if (catalogVersion.compareTo(pdfVersion) > 0) {
-                        pdfVersion = catalogVersion;
+                    try {
+                        PdfVersion catalogVersion = PdfVersion.fromPdfName(catalog.getPdfObject().getAsName(PdfName.Version));
+                        if (catalogVersion.compareTo(pdfVersion) > 0) {
+                            pdfVersion = catalogVersion;
+                        }
+                    } catch (IllegalArgumentException ignored){
                     }
                 }
                 PdfStream xmpMetadataStream = catalog.getPdfObject().getAsStream(PdfName.Metadata);

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

@@ -524,6 +524,14 @@ public void removePageWithInvalidOutlineTest() throws IOException, InterruptedEx
         Assert.assertNull(new CompareTool().compareByContent(destination, cmp, DESTINATION_FOLDER, "diff_"));
     }
 
+    @Test
+    public void openDocumentWithInvalidCatalogVersionTest() throws IOException {
+        PdfReader reader = new PdfReader(SOURCE_FOLDER + "sample-with-invalid-catalog-version.pdf");
+        PdfDocument pdfDocument = new PdfDocument(reader);
+        Assert.assertNotNull(pdfDocument);
+    }
+
+
     private static class IgnoreTagStructurePdfDocument extends PdfDocument {
 
         IgnoreTagStructurePdfDocument(PdfReader reader) {