Handle missing components returned by parse_url()

Found by `phpstan analyze --level 7`

Author: bpfoley

pinc/RandomRule.inc

@@ -269,7 +269,11 @@ class RandomRule
                     return '<a href="' . $url . $match[1] . '"';
                 } elseif (str_starts_with($match[1], '/')) {
                     $url_parts = parse_url($url);
-                    return '<a href="' . $url_parts["scheme"] . "://" . $url_parts["host"] . $match[1] . '"';
+                    if (($scheme = $url_parts["scheme"] ?? "")) {
+                        $scheme .= "://";
+                    }
+                    $host = $url_parts["host"] ?? "";
+                    return '<a href="' . $scheme . $host . $match[1] . '"';
                 } elseif (!str_starts_with($match[1], 'http')) {
                     $base_url = dirname($url) . '/';
                     return '<a href="' . $base_url . $match[1] . '"';

pinc/metarefresh.inc

@@ -41,9 +41,9 @@ function metarefresh(int $seconds, string $url, string $title = "", string $body
     $absolute_url_parts = parse_url($absolute_url);
     $code_url_parts = parse_url($code_url);
     if (!$allow_external && !(
-        ($absolute_url_parts["scheme"] == $code_url_parts["scheme"]) &&
-        ($absolute_url_parts["host"] == $code_url_parts["host"]) &&
-        (($absolute_url_parts["port"] ?? "") == ($code_url_parts["port"] ?? ""))
+        ($absolute_url_parts["scheme"] ?? null) == ($code_url_parts["scheme"] ?? null) &&
+        ($absolute_url_parts["host"] ?? null) == ($code_url_parts["host"] ?? null) &&
+        ($absolute_url_parts["port"] ?? null) == ($code_url_parts["port"] ?? null)
     )) {
         $absolute_url = "$code_url/index.php";
     }