Dont parse twice in test, fix some bugs with special pdfs

.gitignore

@@ -1,2 +1,4 @@
 .idea
 testfiles/*.pdf
+testfiles/*.pdf.broken
+testfiles/*.pdf.tmp

sign/helpers.go

@@ -14,8 +14,15 @@ import (
 func findFirstPage(parent pdf.Value) (pdf.Value, error) {
 	value_type := parent.Key("Type").String()
 	if value_type == "/Pages" {
-		recurse_parent, recurse_err := findFirstPage(parent.Key("Kids").Index(0))
-		return recurse_parent, recurse_err
+
+		for i := 0; i < parent.Key("Kids").Len(); i++ {
+			recurse_parent, recurse_err := findFirstPage(parent.Key("Kids").Index(i))
+			if recurse_err == nil {
+				return recurse_parent, recurse_err
+			}
+		}
+
+		return parent, errors.New("Could not find first page.")
 	}
 
 	if value_type == "/Page" {
@@ -83,6 +90,10 @@ func writePartFromSourceFileToTargetFile(input_file *os.File, output_file *os.Fi
 	// Track read/written bytes so we know when we're done.
 	read_bytes := int64(0)
 
+	if length <= 0 {
+		return nil
+	}
+
 	// Create a buffer for the chunks.
 	buf := make([]byte, max_chunk_length)
 	for {

sign/pdfcatalog.go

@@ -1,7 +1,6 @@
 package sign
 
 import (
-	"errors"
 	"strconv"
 )
 
@@ -20,15 +19,14 @@ func (context *SignContext) createCatalog() (catalog string, err error) {
 		}
 	}
 
-	if !found_pages {
-		return "", errors.New("Didn't find pages in PDF trailer Root.")
-	}
-
 	rootPtr := root.GetPtr()
 	context.CatalogData.RootString = strconv.Itoa(int(rootPtr.GetID())) + " " + strconv.Itoa(int(rootPtr.GetGen())) + " R"
 
-	pages := root.Key("Pages").GetPtr()
-	catalog += " /Pages " + strconv.Itoa(int(pages.GetID())) + " " + strconv.Itoa(int(pages.GetGen())) + " R"
+	if found_pages {
+		pages := root.Key("Pages").GetPtr()
+		catalog += " /Pages " + strconv.Itoa(int(pages.GetID())) + " " + strconv.Itoa(int(pages.GetGen())) + " R"
+	}
+
 	catalog += " /AcroForm <<"
 	catalog += " /Fields [" + strconv.Itoa(int(context.VisualSignData.ObjectId)) + " 0 R]"
 

sign/pdfvisualsignature.go

@@ -1,7 +1,6 @@
 package sign
 
 import (
-	"errors"
 	"strconv"
 )
 
@@ -21,22 +20,21 @@ func (context *SignContext) createVisualSignature() (visual_signature string, er
 		}
 	}
 
-	if !found_pages {
-		return "", errors.New("Didn't find pages in PDF trailer Root.")
-	}
 
 	rootPtr := root.GetPtr()
 	context.CatalogData.RootString = strconv.Itoa(int(rootPtr.GetID())) + " " + strconv.Itoa(int(rootPtr.GetGen())) + " R"
 
-	first_page, err := findFirstPage(root.Key("Pages"))
-	if err != nil {
-		return "", err
+	if found_pages {
+		first_page, err := findFirstPage(root.Key("Pages"))
+		if err != nil {
+			return "", err
+		}
+
+		first_page_ptr := first_page.GetPtr()
+
+		visual_signature += " /P " + strconv.Itoa(int(first_page_ptr.GetID())) + " " + strconv.Itoa(int(first_page_ptr.GetGen())) + " R"
 	}
 
-	first_page_ptr := first_page.GetPtr()
-
-	visual_signature += " /P " + strconv.Itoa(int(first_page_ptr.GetID())) + " " + strconv.Itoa(int(first_page_ptr.GetGen())) + " R"
-
 	visual_signature += " /F 132"
 	visual_signature += " /FT /Sig"
 	visual_signature += " /T " + pdfString("Signature")

sign/pdfxref.go

@@ -27,6 +27,7 @@ func (context *SignContext) writeXref() error {
 }
 
 func (context *SignContext) writeXrefTable() error {
+	// @todo: maybe we need a prev here too.
 	xref_size := "xref\n0 " + strconv.FormatInt(context.PDFReader.XrefInformation.ItemCount, 10)
 	new_xref_size := "xref\n0 " + strconv.FormatInt(context.PDFReader.XrefInformation.ItemCount+4, 10)
 

sign/sign_test.go

@@ -123,30 +123,11 @@ func TestSignPDF(t *testing.T) {
 	for _, f := range files {
 		ext := filepath.Ext(f.Name())
 		if ext != ".pdf" {
-			fmt.Printf("Skipping file %s", f.Name())
+			fmt.Printf("Skipping file %s\n", f.Name())
 			continue
 		}
 
-		input_file, err := os.Open("../testfiles/" + f.Name())
-		if err != nil {
-			t.Errorf("%s: %s", f.Name(), err.Error())
-			return
-		}
-
-		finfo, err := input_file.Stat()
-		if err != nil {
-			input_file.Close()
-			t.Errorf("%s: %s", f.Name(), err.Error())
-			return
-		}
-		size := finfo.Size()
-
-		_, err = pdf.NewReader(input_file, size)
-		if err != nil {
-			input_file.Close()
-			t.Errorf("%s: %s", f.Name(), err.Error())
-			return
-		}
+		fmt.Printf("Signing file %s\n", f.Name())
 
 		err = SignFile("../testfiles/"+f.Name(), "../testfiles/"+f.Name()+".tmp", SignData{
 			Signature: SignDataSignature{
@@ -174,11 +155,8 @@ func TestSignPDF(t *testing.T) {
 		defer os.Remove("../testfiles/"+f.Name()+".tmp")
 
 		if err != nil {
-			input_file.Close()
 			t.Errorf("%s: %s", f.Name(), err.Error())
 			return
 		}
-
-		input_file.Close()
 	}
 }