From b2dfeaf1b92781a89e2620360f079ec8f27c1f7d Mon Sep 17 00:00:00 2001
From: Hielke Morsink <hielke.morsink@gmail.com>
Date: Sun, 5 Sep 2021 12:44:58 +0200
Subject: [PATCH] Introduce String::URLEncode

---
 src/openrct2/core/String.cpp | 28 ++++++++++++++++++++++++++++
 src/openrct2/core/String.hpp |  2 ++
 2 files changed, 30 insertions(+)

diff --git a/src/openrct2/core/String.cpp b/src/openrct2/core/String.cpp
index bb773e5df9..a1e9ff1370 100644
--- a/src/openrct2/core/String.cpp
+++ b/src/openrct2/core/String.cpp
@@ -14,7 +14,10 @@
 #endif // __MINGW32__
 
 #include <algorithm>
+#include <cctype>
 #include <cwctype>
+#include <iomanip>
+#include <sstream>
 #include <stdexcept>
 #include <vector>
 #ifndef _WIN32
@@ -823,6 +826,31 @@ namespace String
 
         return trunc;
     }
+
+    std::string URLEncode(std::string_view value)
+    {
+        std::ostringstream escaped;
+        escaped.fill('0');
+        escaped << std::hex;
+
+        for (auto c : value)
+        {
+            // Keep alphanumeric and other accepted characters intact
+            if (std::isalnum(c) || c == '-' || c == '_' || c == '.' || c == '~')
+            {
+                escaped << c;
+            }
+            else
+            {
+                // Any other characters are percent-escaped
+                escaped << std::uppercase;
+                escaped << '%' << std::setw(2) << int32_t(static_cast<unsigned char>(c));
+                escaped << std::nouppercase;
+            }
+        }
+
+        return escaped.str();
+    }
 } // namespace String
 
 char32_t CodepointView::iterator::GetNextCodepoint(const char* ch, const char** next)
diff --git a/src/openrct2/core/String.hpp b/src/openrct2/core/String.hpp
index d4ce69210e..8c590ee207 100644
--- a/src/openrct2/core/String.hpp
+++ b/src/openrct2/core/String.hpp
@@ -178,6 +178,8 @@ namespace String
      */
     std::string_view UTF8Truncate(std::string_view v, size_t size);
 
+    // Escapes special characters in a string to the percentage equivalent that can be used in URLs.
+    std::string URLEncode(std::string_view value);
 } // namespace String
 
 class CodepointView