Validate that names are valid UTF-8 (#6682)

Add an `isUTF8` utility and use it in both the text and binary parsers.
Add missing checks for overlong encodings and overlarge code points in
our WTF8 reader, which the new utility uses. Re-enable the spec tests
that test UTF-8 validation.

1 files changed, 5 insertions, 4 deletions

diff --git a/src/parser/lexer.h b/src/parser/lexer.h
index 83cbcfc53..37c3fe04a 100644
--- a/src/parser/lexer.h
+++ b/src/parser/lexer.h
@@ -25,6 +25,7 @@
 
 #include "support/name.h"
 #include "support/result.h"
+#include "support/string.h"
 
 #ifndef parser_lexer_h
 #define parser_lexer_h
@@ -124,11 +125,11 @@ public:
   std::optional<std::string> takeString();
 
   std::optional<Name> takeName() {
-    // TODO: Validate UTF.
-    if (auto str = takeString()) {
-      return Name(*str);
+    auto str = takeString();
+    if (!str || !String::isUTF8(*str)) {
+      return std::nullopt;
     }
-    return std::nullopt;
+    return Name(*str);
   }
 
   bool takeSExprStart(std::string_view expected) {