Fix URL-autolinking regex

t.php

@@ -52,35 +52,24 @@ if (count($shareparts) > 1) {
     gracefuldeath_httpcode(400);
 }
 
-function turnUrlIntoHyperlink($string){
-    //https://stackoverflow.com/questions/23366790/php-find-all-links-in-the-text
-    //The Regular Expression filter
-    $reg_exUrl = "/(?i)\b((?:https?:\/\/|www\d{0,3}[.]|[a-z0-9.\-]+[.][a-z]{2,4}\/)(?:[^\s()<>]+|\(([^\s()<>]+|(\([^\s()<>]+\)))*\))+(?:\(([^\s()<>]+|(\([^\s()<>]+\)))*\)|[^\s`!()\[\]{};:'\".,<>?«»""'']))/";
+function turnUrlIntoHyperlink($string) {
+    $pattern = '~\b((?:https?://|ftp://|www\.)[^\s<>"\']+)~i';
 
-    // Check if there is a url in the text
-    if(preg_match_all($reg_exUrl, $string, $url)) {
-        // Loop through all matches
-        foreach($url[0] as $newLinks){
-            // Decode the URL since the string is already HTML-encoded
-            $decodedLink = html_entity_decode($newLinks, ENT_QUOTES, 'UTF-8');
-            if(strstr($decodedLink, ":" ) === false){
-                $link = 'http://'.$decodedLink;
-            }else{
-                $link = $decodedLink;
-            }
-            // Validate URL scheme to prevent javascript: and data: URLs
-            $parsedUrl = parse_url($link);
-            if (isset($parsedUrl['scheme']) && !in_array(strtolower($parsedUrl['scheme']), ['http', 'https', 'ftp'])) {
-                continue; // Skip invalid/dangerous schemes
-            }
-            // Create Search and Replace strings with proper encoding
-            $search  = $newLinks;
-            $replace = '<a href="'.safe_html_output($link).'">'.safe_html_output($decodedLink).'</a>';
-            $string = str_replace($search, $replace, $string);
+    return preg_replace_callback($pattern, function ($matches) {
+        $display = $matches[1];
+        $href = $display;
+
+        if (stripos($href, 'www.') === 0) {
+            $href = 'http://' . $href;
         }
-    }
-    return $string;
+
+        $parsedUrl = parse_url($href);
+        if (!isset($parsedUrl['scheme']) || !in_array(strtolower($parsedUrl['scheme']), ['http', 'https', 'ftp'], true)) {
+            return $display;
+        }
+
+        return '<a href="' . safe_html_output($href) . '">' . safe_html_output($display) . '</a>';
+    }, $string);
 }
 
-
 ?>