LibWeb: Don't crash on unknown CSS display types, fall back to inline

This patch also adds CSS::Display::to_string() so we can log the
unimplemented CSS display value (if you have LIBWEB_CSS_DEBUG enabled).

Userland/Libraries/LibWeb/CMakeLists.txt

@@ -28,6 +28,7 @@ set(SOURCES
     CSS/CSSSupportsRule.cpp
     CSS/ResolvedCSSStyleDeclaration.cpp
     CSS/DefaultStyleSheetSource.cpp
+    CSS/Display.cpp
     CSS/Length.cpp
     CSS/MediaList.cpp
     CSS/MediaQuery.cpp

Userland/Libraries/LibWeb/CSS/Display.cpp

@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2022, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/CSS/Display.h>
+
+namespace Web::CSS {
+
+String Display::to_string() const
+{
+    StringBuilder builder;
+    switch (m_type) {
+    case Type::OutsideAndInside:
+        switch (m_value.outside_inside.outside) {
+        case Outside::Block:
+            builder.append("block"sv);
+            break;
+        case Outside::Inline:
+            builder.append("inline"sv);
+            break;
+        case Outside::RunIn:
+            builder.append("run-in"sv);
+            break;
+        }
+        builder.append(' ');
+        switch (m_value.outside_inside.inside) {
+        case Inside::Flow:
+            builder.append("flow"sv);
+            break;
+        case Inside::FlowRoot:
+            builder.append("flow-root"sv);
+            break;
+        case Inside::Table:
+            builder.append("table"sv);
+            break;
+        case Inside::Flex:
+            builder.append("flex"sv);
+            break;
+        case Inside::Grid:
+            builder.append("grid"sv);
+            break;
+        case Inside::Ruby:
+            builder.append("ruby"sv);
+            break;
+        }
+        if (m_value.outside_inside.list_item == ListItem::Yes)
+            builder.append(" list-item"sv);
+        break;
+    case Type::Internal:
+        switch (m_value.internal) {
+        case Internal::TableRowGroup:
+            builder.append("table-row-group"sv);
+            break;
+        case Internal::TableHeaderGroup:
+            builder.append("table-header-group"sv);
+            break;
+        case Internal::TableFooterGroup:
+            builder.append("table-footer-group"sv);
+            break;
+        case Internal::TableRow:
+            builder.append("table-row"sv);
+            break;
+        case Internal::TableCell:
+            builder.append("table-cell"sv);
+            break;
+        case Internal::TableColumnGroup:
+            builder.append("table-column-group"sv);
+            break;
+        case Internal::TableColumn:
+            builder.append("table-column"sv);
+            break;
+        case Internal::TableCaption:
+            builder.append("table-caption"sv);
+            break;
+        case Internal::RubyBase:
+            builder.append("ruby-base"sv);
+            break;
+        case Internal::RubyText:
+            builder.append("ruby-text"sv);
+            break;
+        case Internal::RubyBaseContainer:
+            builder.append("ruby-base-container"sv);
+            break;
+        case Internal::RubyTextContainer:
+            builder.append("ruby-text-container"sv);
+            break;
+        }
+        break;
+    case Type::Box:
+        switch (m_value.box) {
+        case Box::Contents:
+            builder.append("contents"sv);
+            break;
+        case Box::None:
+            builder.append("none"sv);
+            break;
+        }
+        break;
+    };
+    return builder.to_string();
+}
+
+}

Userland/Libraries/LibWeb/CSS/Display.h

@@ -7,6 +7,7 @@
 #pragma once
 
 #include <AK/Assertions.h>
+#include <AK/String.h>
 
 namespace Web::CSS {
 
@@ -15,6 +16,8 @@ public:
     Display() = default;
     ~Display() = default;
 
+    String to_string() const;
+
     bool operator==(Display const& other) const
     {
         if (m_type != other.m_type)

Userland/Libraries/LibWeb/DOM/Element.cpp

@@ -1,10 +1,11 @@
 /*
- * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2018-2022, Andreas Kling <kling@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
 #include <AK/AnyOf.h>
+#include <AK/Debug.h>
 #include <AK/StringBuilder.h>
 #include <LibWeb/CSS/Parser/Parser.h>
 #include <LibWeb/CSS/PropertyID.h>
@@ -227,7 +228,8 @@ RefPtr<Layout::Node> Element::create_layout_node(NonnullRefPtr<CSS::StylePropert
         if (display.is_flow_inside())
             return adopt_ref(*new Layout::InlineNode(document(), *this, move(style)));
 
-        TODO();
+        dbgln_if(LIBWEB_CSS_DEBUG, "FIXME: Support display: {}", display.to_string());
+        return adopt_ref(*new Layout::InlineNode(document(), *this, move(style)));
     }
 
     if (display.is_flow_inside() || display.is_flow_root_inside() || display.is_flex_inside())