Fix bug in extracting required plugins from composer.json that led to spurious error in log (#7364)

CHANGELOG

@@ -1,6 +1,8 @@
 CHANGELOG Roundcube Webmail
 ===========================
 
+- Fix bug in extracting required plugins from composer.json that led to spurious error in log (#7364)
+
 RELEASE 1.4.4
 -------------
 - Fix bug where attachments with Content-Id were attached to the message on reply (#7122)

program/lib/Roundcube/rcube_plugin_api.php

@@ -245,7 +245,7 @@ class rcube_plugin_api
 
     /**
      * Get information about a specific plugin.
-     * This is either provided my a plugin's info() method or extracted from a package.xml or a composer.json file
+     * This is either provided by a plugin's info() method or extracted from a package.xml or a composer.json file
      *
      * @param string Plugin name
      * @return array Meta information about a plugin or False if plugin was not found
@@ -316,17 +316,29 @@ class rcube_plugin_api
         if (!$info) {
             $composer = INSTALL_PATH . "/plugins/$plugin_name/composer.json";
             if (is_readable($composer) && ($json = @json_decode(file_get_contents($composer), true))) {
+                // Build list of plugins required
+                $require = array();
+                foreach (array_keys((array) $json['require']) as $dname) {
+                    if (!preg_match('|^([^/]+)/([a-zA-Z0-9_-]+)$|', $dname, $m)) {
+                        continue;
+                    }
+
+                    $vendor = $m[1];
+                    $name = $m[2];
+
+                    if ($name != 'plugin-installer' && $vendor != 'pear' && $vendor != 'pear-pear') {
+                        $dpath = unslashify($dir->path) . "/$name/$name.php";
+                        if (is_readable($dpath)) {
+                            $require[] = $name;
+                        }
+                    }
+                }
+
                 list($info['vendor'], $info['name']) = explode('/', $json['name']);
                 $info['version'] = $json['version'];
                 $info['license'] = $json['license'];
                 $info['uri']     = $json['homepage'];
-                $info['require'] = array_filter(array_keys((array)$json['require']), function($pname) {
-                    if (strpos($pname, '/') == false) {
-                        return false;
-                    }
-                    list($vendor, $name) = explode('/', $pname);
-                    return !($name == 'plugin-installer' || $vendor == 'pear-pear');
-                });
+                $info['require'] = $require;
             }
 
             // read local composer.lock file (once)