Fix append pages when stream is not readable

Fixes #191

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixes hard crash to exception when creating a stream with null object and calling createWriter with it
 - Fixes missing buffer information for recrypt typescript definition
 - Fixes missing options for append pdf pages
+- Fixes NPE when stream is not readable in write stream object (PDFDocumentHandler)
 
 ## [2.5.0] - 2022-06-23
 

src/deps/PDFWriter/PDFDocumentHandler.cpp

@@ -2032,6 +2032,10 @@ EStatusCode PDFDocumentHandler::WriteStreamObject(PDFStreamInput* inStream, IObj
 	if(!readingDecrypted) {
 		streamReader = mParser->StartReadingFromStreamForPlainCopying(inStream);
 	}
+
+	if (streamReader == NULL) {
+               status = PDFHummus::eFailure;
+	}
 
 	while (it.MoveNext() && PDFHummus::eSuccess == status)
 	{

tests/AppendPagesTest.js

@@ -1,11 +1,21 @@
+const muhammara = require('../muhammara');
+const expect = require('chai').expect;
+
 describe('AppendPagesTest', function() {
 	it('should complete without error', function() {
-		var pdfWriter = require('../muhammara').createWriter(__dirname + '/output/AppendPagesTest.pdf');
-
+		var pdfWriter = muhammara.createWriter(__dirname + '/output/AppendPagesTest.pdf');
 		pdfWriter.appendPDFPagesFromPDF(__dirname + '/TestMaterials/Original.pdf');
 		pdfWriter.appendPDFPagesFromPDF(__dirname + '/TestMaterials/XObjectContent.PDF');
 		pdfWriter.appendPDFPagesFromPDF(__dirname + '/TestMaterials/BasicTIFFImagesTest.PDF');
 
 		pdfWriter.end();
 	});
+
+	it('should throw an error instead of a crash', () => {
+		var writerBuffer = new muhammara.PDFWStreamForBuffer([]);
+		var pdfWriter = muhammara.createWriter(writerBuffer)
+		expect(() =>
+			pdfWriter.appendPDFPagesFromPDF(__dirname + '/TestMaterials/appendbreaks.pdf')
+		).to.throw('unable to append')
+	})
 });