Index: tests/Zend/Rest/ServerTest.php
===================================================================
--- tests/Zend/Rest/ServerTest.php	(revision 21404)
+++ tests/Zend/Rest/ServerTest.php	(working copy)
@@ -542,9 +542,10 @@
 
     /**
      * @see ZF-1949
+     * @see ZF-9374
      * @group ZF-1949
      */
-    public function testMissingArgumentsWithDefaultsShouldNotResultInFaultResponse()
+    public function testMissingAnonArgumentsWithDefaultsShouldNotResultInFaultResponse()
     {
         $server = new Zend_Rest_Server();
         $server->setClass('Zend_Rest_Server_Test');
@@ -552,10 +553,38 @@
         $server->handle(array('method' => 'testFunc7', 'arg1' => "Davey"));
         $result = ob_get_clean();
         $this->assertContains('<status>success</status>', $result, var_export($result, 1));
-        $this->assertContains('<response>Hello today, How are you Davey</response>', $result, var_export($result, 1));
+        $this->assertContains('<response>Hello Davey, How are you today</response>', $result, var_export($result, 1));
     }
 
     /**
+     * @see ZF-9374
+     */
+    public function testMissingZeroBasedAnonArgumentsWithDefaultsShouldNotResultInFaultResponse()
+    {
+        $server = new Zend_Rest_Server();
+        $server->setClass('Zend_Rest_Server_Test');
+        ob_start();
+        $server->handle(array('method' => 'testFunc7', 'arg0' => "Davey"));
+        $result = ob_get_clean();
+        $this->assertContains('<status>success</status>', $result, var_export($result, 1));
+        $this->assertContains('<response>Hello Davey, How are you today</response>', $result, var_export($result, 1));
+    }
+
+    /**
+     * @see ZF-9374
+     */
+    public function testMissingNamesArgumentsWithDefaultsShouldNotResultInFaultResponse()
+    {
+        $server = new Zend_Rest_Server();
+        $server->setClass('Zend_Rest_Server_Test');
+        ob_start();
+        $server->handle(array('method' => 'testFunc7', 'who' => "Davey"));
+        $result = ob_get_clean();
+        $this->assertContains('<status>success</status>', $result, var_export($result, 1));
+        $this->assertContains('<response>Hello Davey, How are you today</response>', $result, var_export($result, 1));
+    }
+
+    /**
      * @group ZF-3751
      */
     public function testCallingUnknownMethodDoesNotThrowUnknownButSpecificErrorExceptionMessage()
Index: library/Zend/Rest/Server.php
===================================================================
--- library/Zend/Rest/Server.php	(revision 21404)
+++ library/Zend/Rest/Server.php	(working copy)
@@ -189,28 +189,35 @@
 
                     $func_args = $this->_functions[$this->_method]->getParameters();
 
+                    // calling_args will be a zero-based array of the parameters
                     $calling_args = array();
                     $missing_args = array();
-                    foreach ($func_args as $arg) {
+                    foreach ($func_args as $i => $arg) {
                         if (isset($request[strtolower($arg->getName())])) {
-                            $calling_args[] = $request[strtolower($arg->getName())];
+                            $calling_args[$i] = $request[strtolower($arg->getName())];
                         } elseif ($arg->isOptional()) {
-                            $calling_args[] = $arg->getDefaultValue();
+                            $calling_args[$i] = $arg->getDefaultValue();
                         } else {
                             $missing_args[] = $arg->getName();
                         }
                     }
 
+                    // anon_args may be 1-based (per docs), or 0-based (per incorrect Zend_Rest_Client @see ZF-9373)
+                    $anon_args = array();
                     foreach ($request as $key => $value) {
                         if (substr($key, 0, 3) == 'arg') {
                             $key = str_replace('arg', '', $key);
-                            $calling_args[$key] = $value;
+                            $anon_args[$key] = $value;
                             if (($index = array_search($key, $missing_args)) !== false) {
                                 unset($missing_args[$index]);
                             }
                         }
                     }
 
+                    // re-key the anon_args to be zero-based, and add in any values already set in calling_args (optional defaults)
+                    ksort($anon_args);
+                    $calling_args = array_values($anon_args) + $calling_args;
+
                     // Sort arguments by key -- @see ZF-2279
                     ksort($calling_args);