1 files changed, 20 insertions, 10 deletions
diff --git a/lib/child_process.js b/lib/child_process.js
index 0c1b4c99c..53e0bb24f 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -591,7 +591,7 @@ exports.exec = function(command /*, options, callback */) {
 
 
 exports.execFile = function(file /* args, options, callback */) {
-  var args, optionArg, callback;
+  var args = [], optionArg, callback;
   var options = {
     encoding: 'utf8',
     timeout: 0,
@@ -601,18 +601,28 @@ exports.execFile = function(file /* args, options, callback */) {
     env: null
   };
 
-  // Parse the parameters.
+  // Parse the optional positional parameters.
+  var pos = 1;
+  if (pos < arguments.length && Array.isArray(arguments[pos])) {
+    args = arguments[pos++];
+  }
+  else if(pos < arguments.length && arguments[pos] == null) {
+    pos++;
+  }
 
-  if (typeof arguments[arguments.length - 1] === 'function') {
-    callback = arguments[arguments.length - 1];
+  if (pos < arguments.length && typeof arguments[pos] === 'object') {
+    options = util._extend(options, arguments[pos++]);
+  }
+  else if(pos < arguments.length && arguments[pos] == null) {
+    pos++;
   }
 
-  if (Array.isArray(arguments[1])) {
-    args = arguments[1];
-    options = util._extend(options, arguments[2]);
-  } else {
-    args = [];
-    options = util._extend(options, arguments[1]);
+  if (pos < arguments.length && typeof arguments[pos] === 'function') {
+    callback = arguments[pos++];
+  }
+
+  if (pos === 1 && arguments.length > 1) {
+    throw new TypeError('Incorrect value of args option');
   }
 
   var child = spawn(file, args, {