LibUnicode: Support IgnorePunnycode option in ToAscii algorithm

This was introduced in UTS 46 revision 31.

Author: shannonbooth

Libraries/LibUnicode/IDNA.cpp

@@ -45,12 +45,17 @@ ErrorOr<String> to_ascii(Utf8View domain_name, ToAsciiOptions const& options)
         errors &= ~UIDNA_ERROR_LEADING_HYPHEN;
         errors &= ~UIDNA_ERROR_TRAILING_HYPHEN;
     }
+
     if (options.verify_dns_length == VerifyDnsLength::No) {
         errors &= ~UIDNA_ERROR_EMPTY_LABEL;
         errors &= ~UIDNA_ERROR_LABEL_TOO_LONG;
         errors &= ~UIDNA_ERROR_DOMAIN_NAME_TOO_LONG;
     }
 
+    if (options.ignore_invalid_punycode == IgnoreInvalidPunycode::Yes) {
+        errors &= ~UIDNA_ERROR_PUNYCODE;
+    }
+
     if (icu_failure(status) || errors != 0)
         return Error::from_string_literal("Unable to convert domain to ASCII");
 

Libraries/LibUnicode/IDNA.h

@@ -42,13 +42,19 @@ enum class VerifyDnsLength {
     Yes,
 };
 
+enum class IgnoreInvalidPunycode {
+    No,
+    Yes,
+};
+
 struct ToAsciiOptions {
     CheckHyphens check_hyphens { CheckHyphens::Yes };
     CheckBidi check_bidi { CheckBidi::Yes };
     CheckJoiners check_joiners { CheckJoiners::Yes };
     UseStd3AsciiRules use_std3_ascii_rules { UseStd3AsciiRules::No };
     TransitionalProcessing transitional_processing { TransitionalProcessing::No };
     VerifyDnsLength verify_dns_length { VerifyDnsLength::Yes };
+    IgnoreInvalidPunycode ignore_invalid_punycode { IgnoreInvalidPunycode::No };
 };
 
 ErrorOr<String> to_ascii(Utf8View domain_name, ToAsciiOptions const& = {});