LibWeb: Support named character references (e.g "&")

Libraries/LibWeb/CMakeLists.txt

@@ -85,6 +85,7 @@ set(SOURCES
     Layout/LineBox.cpp
     Layout/LineBoxFragment.cpp
     Parser/CSSParser.cpp
+    Parser/Entities.cpp
     Parser/HTMLDocumentParser.cpp
     Parser/HTMLParser.cpp
     Parser/HTMLToken.cpp

Libraries/LibWeb/Parser/Entities.h

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/StringView.h>
+#include <AK/Vector.h>
+
+namespace Web {
+namespace HTML {
+
+struct EntityMatch {
+    Vector<u32, 2> codepoints;
+    StringView entity;
+};
+
+Optional<EntityMatch> codepoints_from_entity(const StringView&);
+
+}
+}

Libraries/LibWeb/Parser/HTMLTokenizer.cpp

@@ -24,6 +24,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <LibWeb/Parser/Entities.h>
 #include <LibWeb/Parser/HTMLToken.h>
 #include <LibWeb/Parser/HTMLTokenizer.h>
 #include <ctype.h>
@@ -1185,15 +1186,55 @@ _StartOfFunction:
 
             BEGIN_STATE(NamedCharacterReference)
             {
-                // FIXME:This is not the right way to implement this state!!
+                auto match = HTML::codepoints_from_entity(m_input.substring_view(m_cursor - 1, m_input.length() - m_cursor + 1));
+
+                if (match.has_value()) {
+                    m_cursor += match.value().entity.length();
+                    for (auto ch : match.value().entity)
+                        m_temporary_buffer.append(ch);
+
+                    if (consumed_as_part_of_an_attribute() && match.value().entity.ends_with(';')) {
+                        auto next_codepoint = peek_codepoint(0);
+                        if (next_codepoint.has_value() && next_codepoint.value() == '=') {
+                            FLUSH_CODEPOINTS_CONSUMED_AS_A_CHARACTER_REFERENCE;
+                            SWITCH_TO_RETURN_STATE;
+                        }
+                    }
+
+                    if (!match.value().entity.ends_with(';')) {
+                        TODO();
+                    }
+
+                    m_temporary_buffer.clear();
+                    m_temporary_buffer.append(match.value().codepoints);
+
+                    FLUSH_CODEPOINTS_CONSUMED_AS_A_CHARACTER_REFERENCE;
+                    SWITCH_TO_RETURN_STATE;
+                } else {
+                    FLUSH_CODEPOINTS_CONSUMED_AS_A_CHARACTER_REFERENCE;
+                    SWITCH_TO(AmbiguousAmpersand);
+                }
+            }
+            END_STATE
+
+            BEGIN_STATE(AmbiguousAmpersand)
+            {
+                ON_ASCII_ALPHANUMERIC
+                {
+                    if (consumed_as_part_of_an_attribute()) {
+                        m_current_token.m_tag.attributes.last().value_builder.append(current_input_character.value());
+                        continue;
+                    } else {
+                        EMIT_CURRENT_CHARACTER;
+                    }
+                }
                 ON(';')
                 {
-                    SWITCH_TO_RETURN_STATE;
+                    TODO();
                 }
                 ANYTHING_ELSE
                 {
-                    dbg() << "NamedCharacterReference: '" << (char)current_input_character.value() << "'";
-                    continue;
+                    RECONSUME_IN_RETURN_STATE;
                 }
             }
             END_STATE