From d1f257acc56c81aa3dee96ac4d8f406c80c8d5bc Mon Sep 17 00:00:00 2001
From: rvdforst <rolf.v.d.forst@fau.de>
Date: Thu, 27 Jun 2024 12:46:21 +0200
Subject: [PATCH 1/3] Update ICS.php

---
 includes/ICS/ICS.php | 76 +++++++++++++++++++++-----------------------
 1 file changed, 36 insertions(+), 40 deletions(-)

diff --git a/includes/ICS/ICS.php b/includes/ICS/ICS.php
index 4178981..1527a6c 100644
--- a/includes/ICS/ICS.php
+++ b/includes/ICS/ICS.php
@@ -6,8 +6,15 @@
 
 class ICS
 {
+    // Date and time format
     public const DT_FORMAT = 'Ymd\THis\Z';
 
+    // Carriage return and line feed
+    const CRLF = "\r\n";
+
+    // Length of line in bytes
+    const LINE_LENGTH = 70;
+
     /**
      * iCalendar data array.
      *
@@ -86,7 +93,7 @@ public function build(): string
             fn ($row) => $this->split($row),
             $this->render()
         );
-        return implode("\r\n", $rows);
+        return implode(self::CRLF, $rows);
     }
 
     /**
@@ -139,13 +146,12 @@ private function sanitizeValue(string $value, string $key = ''): string
             case 'dtstart':
                 $value = $this->formatTimestamp($value);
                 break;
-            case 'summary':
             case 'description':
             case 'location':
-                $value = $this->escStr($value, true);
+                $value = $this->escStr($value);
                 break;
             default:
-                $value = $this->escStr($value);
+                $value = $value;
         }
 
         return $value;
@@ -164,60 +170,50 @@ private function formatTimestamp(string $timestamp): string
     }
 
     /**
-     * Escape special characters.
+     * Escapes , and ; characters in text type fields.
      *
-     * @param string $input
-     * @param boolean $specialChars
+     * @param string $value The string to escape
      * @return string
      */
-    private function escStr(string $input, $specialChars = false): string
+    private function escStr(string $value): string
     {
-        if ($specialChars) {
-            $input = preg_replace('/([\,;])/', '\\\$1', $input);
-        }
-        $input = str_replace("\n", "\\n", $input);
-        $input = str_replace("\r", "\\r", $input);
-        return $input;
+        $value = preg_replace('/((?<!\\\),|(?<!\\\);)/', '\\\$1', $value);
+        $value = preg_replace('/((?<!\\\)\\\(?!,|;|n|N|\\\))/', '\\\\$1', $value);
+        return $value;
     }
 
     /**
-     * Split content lines.
+     * Splits a string into new lines if necessary.
      * RFC-5545 (3.1. Content Lines)
      *
-     * @param string $input
-     * @param integer $lineLimit
+     * @param string $value
      * @return string
      */
-    private function split(string $input, int $lineLimit = 70): string
+    private function split(string $value): string
     {
+        // Newlines need to be converted to literal \n
+        $value = str_replace("\n", "\\n", str_replace("\r\n", "\n", $value));
+
+        // Get number of bytes
+        $length = strlen($value);
+
         $output = '';
-        $line = '';
-        $pos = 0;
-
-        while ($pos < mb_strlen($input)) {
-            // Find newlines
-            $newLinepos = mb_strpos($input, "\n", $pos + 1);
-            if (!$newLinepos) {
-                $newLinepos = mb_strlen($input);
-            }
-            $line = mb_substr($input, $pos, $newLinepos - $pos);
 
-            if (mb_strlen($line) <= $lineLimit) {
-                $output .= $line;
-            } else {
-                // The line break limit of the first line is $lineLimit
-                $output .= mb_substr($line, 0, $lineLimit);
-                $line = mb_substr($line, $lineLimit);
+        if ($length > 75) {
+            $start = 0;
 
-                // Subsequent line break limit is $lineLimit - 1 due to leading whitespace
-                $output .= "\n " . mb_substr($line, 0, $lineLimit - 1);
+            while ($start < $length) {
+                $cut = mb_strcut($value, $start, self::LINE_LENGTH, 'UTF-8');
+                $output .= $cut;
+                $start = $start + strlen($cut);
 
-                while (mb_strlen($line) > $lineLimit - 1) {
-                    $line = mb_substr($line, $lineLimit - 1);
-                    $output .= "\n " . mb_substr($line, 0, $lineLimit - 1);
+                // Add space if not last line
+                if ($start < $length) {
+                    $output .= self::CRLF . ' ';
                 }
             }
-            $pos = $newLinepos;
+        } else {
+            $output = $value;
         }
 
         return $output;

From 50a60f4705869f9bf5f1b1229517a3c3db3d49c6 Mon Sep 17 00:00:00 2001
From: rvdforst <rolf.v.d.forst@fau.de>
Date: Thu, 27 Jun 2024 12:46:32 +0200
Subject: [PATCH 2/3] Update Utils.php

---
 includes/Utils.php | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/includes/Utils.php b/includes/Utils.php
index 02568da..b8f7f47 100644
--- a/includes/Utils.php
+++ b/includes/Utils.php
@@ -893,6 +893,10 @@ public static function titleFilter($where, $wp_query)
      */
     public static function validateDate($date)
     {
+        if (empty($date)) {
+            return false;
+        }
+
         if ($date instanceof \DateTime) {
             return true;
         }

From c9363e0bbcd5d41d384f00dfd5260c72151f3e7f Mon Sep 17 00:00:00 2001
From: rvdforst <rolf.v.d.forst@fau.de>
Date: Thu, 27 Jun 2024 12:46:36 +0200
Subject: [PATCH 3/3] Update rrze-calendar.php

---
 rrze-calendar.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rrze-calendar.php b/rrze-calendar.php
index ca3bc1d..e231e2b 100644
--- a/rrze-calendar.php
+++ b/rrze-calendar.php
@@ -4,7 +4,7 @@
 Plugin Name:     RRZE Calendar
 Plugin URI:      https://github.com/RRZE-Webteam/rrze-calendar
 Description:     Import and output of FAU public events.
-Version:         2.2.8
+Version:         2.2.9
 Author:          RRZE Webteam
 Author URI:      https://blogs.fau.de/webworking/
 License:         GNU General Public License v3.0