From 0d0fee369a433ad14650784273036f33fc0abe7f Mon Sep 17 00:00:00 2001
From: Danny Lin <danny0838@gmail.com>
Date: Sun, 31 Mar 2024 18:40:48 +0800
Subject: [PATCH] Fix escaping of \u0000 and a standalone surrogate

- ref: https://www.w3.org/TR/css-syntax-3/#consume-escaped-code-point
---
 parse-css.js | 2 +-
 tests.js     | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/parse-css.js b/parse-css.js
index efbfdf3..489d040 100644
--- a/parse-css.js
+++ b/parse-css.js
@@ -362,7 +362,7 @@ function tokenize(str) {
       }
       if(whitespace(next())) consume();
       var value = parseInt(digits.map(function(x){return String.fromCharCode(x);}).join(''), 16);
-      if( value > maximumallowedcodepoint ) value = 0xfffd;
+      if (value === 0x0 || between(value, 0xd800, 0xdfff) || value > maximumallowedcodepoint ) value = 0xfffd;
       return value;
     } else if(eof()) {
       return 0xfffd;
diff --git a/tests.js b/tests.js
index cb729bc..4c3bd6d 100644
--- a/tests.js
+++ b/tests.js
@@ -398,6 +398,15 @@ var TESTS = [
         "value": "\uFFFD"
       },
     ]
+  }, {
+    parser: '',
+    css: `\\20000 \\0 \\D800 \\DFFF \\110000 `,
+    expected: [
+      {
+        "type": "IDENT",
+        "value": "\u{20000}\uFFFD\uFFFD\uFFFD\uFFFD"
+      },
+    ]
   }
 ];