Fix createWriter cpp / crash / npe when using null as stream object (#…

…190)

Fix createWriter cpp / crash / npe when using null as stream object

Fixes #188

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Changed
 
+- 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
 
 ## [2.5.0] - 2022-06-23

src/ObjectByteWriterWithPosition.cpp

@@ -52,21 +52,29 @@ IOBasicTypes::LongBufferSizeType ObjectByteWriterWithPosition::Write(const IOBas
 
     Local<Value> args[1];
     args[0] = anArray;
-
-	Local<Value> result = func->Call(GET_CURRENT_CONTEXT,  OBJECT_FROM_PERSISTENT(mObject), 1, args).ToLocalChecked();
+    MaybeLocal<Value> maybe;
+    TryCatch try_catch(Isolate::GetCurrent());
+
+    maybe = func->Call(GET_CURRENT_CONTEXT,  OBJECT_FROM_PERSISTENT(mObject), 1, args);
+    Local <Value> result;
+
+    if (!maybe.ToLocal(&result)) {
+       try_catch.ReThrow();
+       return 0;
+    }
     if(result.IsEmpty())
     {
-		THROW_EXCEPTION("wrong return value. it's empty. return the number of written characters");
-		return 0;
+        THROW_EXCEPTION("wrong return value. it's empty. return the number of written characters");
+        return 0;
     }
     else if(result->IsNumber())
     {
         return TO_UINT32(result)->Value();
     }
     else
     {
-		THROW_EXCEPTION("wrong return value. write should return the number of written characters");
-		return 0;
+        THROW_EXCEPTION("wrong return value. write should return the number of written characters");
+        return 0;
     }
 }
 
@@ -81,4 +89,4 @@ IOBasicTypes::LongFilePositionType ObjectByteWriterWithPosition::GetCurrentPosit
     Local<Function> func = Local<Function>::Cast(value);
 
 	return TO_NUMBER(func->Call(GET_CURRENT_CONTEXT, OBJECT_FROM_PERSISTENT(mObject), 0, NULL).ToLocalChecked())->Value();
-}
+}

tests/BasicModificationWithStreams.js

@@ -1,4 +1,5 @@
 var muhammara = require('../muhammara');
+const chai = require('chai');
 
 describe('BasicModificationWithStreams', function() {
 	it('should complete without error', function() {
@@ -14,9 +15,15 @@ describe('BasicModificationWithStreams', function() {
 			color:0x00
 		});
 		pageModifier.endContext().writePage();
-
 		pdfWriter.end();
 		outStream.close();
 		inStream.close();
 	});
+
+	it('null for stream should throw an error and not crash', function () {
+		var res = new muhammara.PDFStreamForResponse(null)
+		chai.expect(
+			muhammara.createWriter.bind(undefined, res)
+		).to.throw(/Cannot read propert.*(write)?.* of null/)
+	})
 });