Fix the bug where copy constructor fails to copy the option of the source

Closes #9

Author: smikitky

multi-integer-range.ts

@@ -37,10 +37,12 @@ export class MultiRange {
 			this.appendRange(data, data);
 		} else if (data instanceof MultiRange) {
 			this.ranges = data.getRanges();
-			this.options = {
-				parseNegative: this.options.parseNegative,
-				parseUnbounded: this.options.parseUnbounded
-			};
+			if (arguments[1] === undefined) {
+				this.options = {
+					parseNegative: data.options.parseNegative,
+					parseUnbounded: data.options.parseUnbounded
+				};
+			}
 		} else if (isArray(data)) {
 			for (let item of <(number|Range)[]>data) {
 				if (isArray(item)) {

test/multi-integer-range.js

@@ -75,6 +75,19 @@ describe('MultiRange', function() {
 			t(mr(mr('5-10')), '5-10'); // aka clone
 		});
 
+		it('must copy the options when using copy constructor', function() {
+			var original = mrd('5-10', { parseNegative: true });
+
+			var b = mrd(original);
+			assert.isTrue(b.options.parseNegative);
+			assert.isFalse(b.options.parseUnbounded);
+
+			// If another options is explicitly provided, respect it
+			var c = mrd(original, { parseNegative: false, parseUnbounded: true });
+			assert.isFalse(c.options.parseNegative);
+			assert.isTrue(c.options.parseUnbounded);
+		});
+
 		it('must throw an error for invalid input', function() {
 			assert.throws(function() { mr('abc'); }, SyntaxError);
 			assert.throws(function() { mr('1.5'); }, SyntaxError);