Small fix for authentication and added a unittest

library/Solarium/Client/Adapter/Http.php

@@ -111,6 +111,10 @@ class Solarium_Client_Adapter_Http extends Solarium_Client_Adapter
             }
         }
 
+        if ( isset( $this->_options['username']) && isset( $this->_options['password'])) {
+            $request->addHeader('Authorization: Basic ' . base64_encode($this->_options['username']. ':' . $this->_options['password'] ));
+        }
+
         $headers = $request->getHeaders();
         if (count($headers) > 0) {
             stream_context_set_option(
@@ -121,12 +125,6 @@ class Solarium_Client_Adapter_Http extends Solarium_Client_Adapter
             );
         }
 
-
-        if ( isset( $this->_options['username']) && isset( $this->_options['password'])) {
-            $request->addHeader('Authorization: Basic ' . base64_encode($this->_options['username']. ':' . $this->_options['password'] ));
-        } 
-
-
         return $context;
     }
 

tests/Solarium/Client/Adapter/HttpTest.php

@@ -150,4 +150,26 @@ class Solarium_Client_Adapter_HttpTest extends PHPUnit_Framework_TestCase
         );
     }
 
+    public function testCreateContextWithAuthorization()
+    {
+        $timeout = 13;
+        $method = Solarium_Client_Request::METHOD_HEAD;
+
+        $request = new Solarium_Client_Request();
+        $request->setMethod($method);
+
+        $this->_adapter->setOptions(array(
+            'username' => 'someone',
+            'password' => 'S0M3p455'
+        ));
+        $this->_adapter->setTimeout($timeout);
+
+        $context = $this->_adapter->createContext($request);
+
+        $this->assertEquals(
+            array('http' => array('method' => $method, 'timeout' => $timeout, 'header' => 'Authorization: Basic c29tZW9uZTpTME0zcDQ1NQ==')),
+            stream_context_get_options($context)
+        );
+    }
+
 }
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