1 files changed, 151 insertions, 0 deletions
diff --git a/xbmc/utils/CSSUtils.cpp b/xbmc/utils/CSSUtils.cpp
new file mode 100644
index 0000000..329d70c
--- /dev/null
+++ b/xbmc/utils/CSSUtils.cpp
@@ -0,0 +1,151 @@
+/*
+ *  Copyright (C) 2005-2021 Team Kodi
+ *  This file is part of Kodi - https://kodi.tv
+ *
+ *  SPDX-License-Identifier: GPL-2.0-or-later
+ *  See LICENSES/README.md for more information.
+ */
+
+#include "CSSUtils.h"
+
+#include <cstdint>
+#include <string>
+
+namespace
+{
+// https://www.w3.org/TR/css-syntax-3/#hex-digit
+bool isHexDigit(char c)
+{
+  return (c >= '0' && c <= '9') || (c >= 'A' && c <= 'F') || (c >= 'a' && c <= 'f');
+}
+
+// https://www.w3.org/TR/css-syntax-3/#hex-digit
+uint32_t convertHexDigit(char c)
+{
+  if (c >= '0' && c <= '9')
+  {
+    return c - '0';
+  }
+  else if (c >= 'A' && c <= 'F')
+  {
+    return 10 + c - 'A';
+  }
+  else
+  {
+    return 10 + c - 'a';
+  }
+}
+
+// https://infra.spec.whatwg.org/#surrogate
+bool isSurrogateCodePoint(uint32_t c)
+{
+  return c >= 0xD800 && c <= 0xDFFF;
+}
+
+// https://www.w3.org/TR/css-syntax-3/#maximum-allowed-code-point
+bool isGreaterThanMaximumAllowedCodePoint(uint32_t c)
+{
+  return c > 0x10FFFF;
+}
+
+// https://www.w3.org/TR/css-syntax-3/#consume-escaped-code-point
+std::string escapeStringChunk(std::string& str, size_t& pos)
+{
+  if (str.size() < pos + 1)
+    return "";
+
+  uint32_t codePoint = convertHexDigit(str[pos + 1]);
+
+  if (str.size() >= pos + 2)
+    pos += 2;
+  else
+    return "";
+
+  int numDigits = 1;
+  while (numDigits < 6 && isHexDigit(str[pos]))
+  {
+    codePoint = 16 * codePoint + convertHexDigit(str[pos]);
+    if (str.size() >= pos + 1)
+    {
+      pos += 1;
+      numDigits += 1;
+    }
+    else
+      break;
+  }
+
+  std::string result;
+
+  // Convert code point to UTF-8 bytes
+  if (codePoint == 0 || isSurrogateCodePoint(codePoint) ||
+      isGreaterThanMaximumAllowedCodePoint(codePoint))
+  {
+    result += u8"\uFFFD";
+  }
+  else if (codePoint < 0x80)
+  {
+    // 1-byte UTF-8: 0xxxxxxx
+    result += static_cast<char>(codePoint);
+  }
+  else if (codePoint < 0x800)
+  {
+    // 2-byte UTF-8: 110xxxxx 10xxxxxx
+    uint32_t x1 = codePoint >> 6; // 6 = num of x's in 2nd byte
+    uint32_t x2 = codePoint - (x1 << 6); // 6 = num of x's in 2nd byte
+    uint32_t b1 = (6 << 5) + x1; // 6 = 0b110 ; 5 = num of x's in 1st byte
+    uint32_t b2 = (2 << 6) + x2; // 2 = 0b10  ; 6 = num of x's in 2nd byte
+    result += static_cast<char>(b1);
+    result += static_cast<char>(b2);
+  }
+  else if (codePoint < 0x10000)
+  {
+    // 3-byte UTF-8: 1110xxxx 10xxxxxx 10xxxxxx
+    uint32_t y1 = codePoint >> 6;
+    uint32_t x3 = codePoint - (y1 << 6);
+    uint32_t x1 = y1 >> 6;
+    uint32_t x2 = y1 - (x1 << 6);
+    uint32_t b1 = (14 << 4) + x1;
+    uint32_t b2 = (2 << 6) + x2;
+    uint32_t b3 = (2 << 6) + x3;
+    result += static_cast<char>(b1);
+    result += static_cast<char>(b2);
+    result += static_cast<char>(b3);
+  }
+  else
+  {
+    // 4-byte UTF-8: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+    uint32_t y2 = codePoint >> 6;
+    uint32_t x4 = codePoint - (y2 << 6);
+    uint32_t y1 = y2 >> 6;
+    uint32_t x3 = y2 - (y1 << 6);
+    uint32_t x1 = y1 >> 6;
+    uint32_t x2 = y1 - (x1 << 6);
+    uint32_t b1 = (30 << 3) + x1;
+    uint32_t b2 = (2 << 6) + x2;
+    uint32_t b3 = (2 << 6) + x3;
+    uint32_t b4 = (2 << 6) + x4;
+    result += static_cast<char>(b1);
+    result += static_cast<char>(b2);
+    result += static_cast<char>(b3);
+    result += static_cast<char>(b4);
+  }
+
+  return result;
+}
+
+} // unnamed namespace
+
+void UTILS::CSS::Escape(std::string& str)
+{
+  std::string result;
+
+  for (size_t pos = 0; pos < str.size(); pos++)
+  {
+    if (str[pos] == '\\')
+      result += escapeStringChunk(str, pos);
+    else
+      result += str[pos];
+  }
+
+  str = result;
+}