Make it possible to include parameters in the OpenURL resolver base URL.

module/VuFind/src/VuFind/Resolver/Driver/AbstractBase.php

@@ -68,7 +68,10 @@ abstract class AbstractBase implements DriverInterface
      */
     public function getResolverUrl($openURL)
     {
-        return $this->baseUrl . '?' . $openURL;
+        $url = $this->baseUrl;
+        $url .= strpos($url, '?') === false ? '?' : '&';
+        $url .= $openURL;
+        return $url;
     }
 
     /**

module/VuFind/src/VuFind/Resolver/Driver/Redi.php

@@ -81,7 +81,7 @@ class Redi extends AbstractBase
      */
     public function fetchLinks($openURL)
     {
-        $url = $this->baseUrl . '?' . $openURL;
+        $url = $this->getResolverUrl($openURL);
         $feed = $this->httpClient->setUri($url)->send()->getBody();
         return $feed;
     }

module/VuFind/src/VuFind/Resolver/Driver/Sfx.php

@@ -72,8 +72,9 @@ class Sfx extends AbstractBase
     public function fetchLinks($openURL)
     {
         // Make the call to SFX and load results
-        $url = $this->baseUrl .
-            '?sfx.response_type=multi_obj_detailed_xml&svc.fulltext=yes&' . $openURL;
+        $url = $this->getResolverUrl(
+            'sfx.response_type=multi_obj_detailed_xml&svc.fulltext=yes&' . $openURL
+        );
         $feed = $this->httpClient->setUri($url)->send()->getBody();
         return $feed;
     }