Allow creating parser without options. Fixes #1373

lib/less/env.js

@@ -30,13 +30,15 @@
         if (!this.files) { this.files = {}; }
 
         if (!this.currentFileInfo) {
-            var filename = options.filename || "input";
-            options.filename = null;
+            var filename = (options && options.filename) || "input";
             var entryPath = filename.replace(/[^\/\\]*$/, "");
+            if (options) {
+                options.filename = null;
+            }
             this.currentFileInfo = {
                 filename: filename,
                 relativeUrls: this.relativeUrls,
-                rootpath: options.rootpath || "",
+                rootpath: (options && options.rootpath) || "",
                 currentDirectory: entryPath,
                 entryPath: entryPath,
                 rootFilename: filename

test/less-test.js

@@ -62,6 +62,7 @@ runTestSet({strictMath: true, dumpLineNumbers: 'all'}, "debug/", null,
 runTestSet({strictMath: true, relativeUrls: false, rootpath: "folder (1)/"}, "static-urls/");
 runTestSet({strictMath: true, compress: true}, "compression/");
 runTestSet({strictMath: false}, "legacy/");
+testNoOptions();
 
 function globalReplacements(input, directory) {
     var p = path.join(process.cwd(), directory),
@@ -184,3 +185,15 @@ function toCSS(options, path, callback) {
         });
     });
 }
+
+function testNoOptions() {
+    totalTests++;
+    try {
+        sys.print("- Integration - creating parser without options: ");
+        new(less.Parser);
+    } catch(e) {
+        fail(stylize("FAIL\n", "red"));
+        return;
+    }
+    ok(stylize("OK\n", "green"));
+}