Merge remote-tracking branch 'origin/4.0-dev' into 390-merge6

Author: wilsonge

administrator/components/com_plugins/forms/plugin.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<form addfieldprefix="Joomla\Component\Content\Administrator\Field">
+<form addfieldprefix="Joomla\Component\Plugins\Administrator\Field">
 	<fieldset>
 		<field
 			name="extension_id"

build/media_source/system/js/fields/joomla-field-module-order.w-c.es6.js

@@ -94,7 +94,7 @@ customElements.define('joomla-field-module-order', class extends HTMLElement {
     const that = this;
 
     Joomla.request({
-      url: `${url}client_id=${clientId}&position=${originalPosition}`,
+      url: `${url}&client_id=${clientId}&position=${originalPosition}`,
       method: 'GET',
       perform: true,
       headers: { 'Content-Type': 'application/x-www-form-urlencoded' },

libraries/src/Installer/Adapter/ComponentAdapter.php

@@ -947,7 +947,11 @@ protected function storeExtension($deleteExisting = false)
 			}
 		}
 
-		$this->extension->namespace = (string) $this->manifest->namespace;
+		// Namespace is optional
+		if (isset($this->manifest->namespace))
+		{
+			$this->extension->namespace = (string) $this->manifest->namespace;
+		}
 
 		// If there is not already a row, generate a heap of defaults
 		if (!$this->currentExtensionId)
@@ -1420,7 +1424,12 @@ public function refreshManifestCache()
 		$manifest_details                        = Installer::parseXMLInstallFile($this->parent->getPath('manifest'));
 		$this->parent->extension->manifest_cache = json_encode($manifest_details);
 		$this->parent->extension->name           = $manifest_details['name'];
-		$this->parent->extension->namespace      = $manifest_details['namespace'];
+
+		// Namespace is optional
+		if (isset($manifest_details['namespace']))
+		{
+			$this->parent->extension->namespace = $manifest_details['namespace'];
+		}
 
 		try
 		{