Fixes #4358: Output Window is removing new lines

src/vs/base/node/decoder.ts

@@ -45,8 +45,12 @@ export class LineDecoder {
 			if (ch === CharCode.CarriageReturn || ch === CharCode.LineFeed) {
 				result.push(value.substring(start, idx));
 				idx++;
-				while (idx < value.length && ((ch = value.charCodeAt(idx)) === CharCode.CarriageReturn || ch === CharCode.LineFeed)) {
-					idx++;
+				if (idx < value.length) {
+					let lastChar = ch;
+					ch = value.charCodeAt(idx);
+					if ((lastChar === CharCode.CarriageReturn && ch === CharCode.LineFeed) || (lastChar === CharCode.LineFeed && ch === CharCode.CarriageReturn)) {
+						idx++;
+					}
 				}
 				start = idx;
 			} else {