From 2a266db05bf0ce937fa28d5070ac5172d1da6ac6 Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Sun, 6 Oct 2019 11:05:57 +0200
Subject: [PATCH] LibHTML: Parse descendant relations in CSS selectors

"div p" now generates a Selector with two components where the second
component is a type=TagName, value="p", relation=Descendant.

We still don't handle matching of these, but at least we parse them.
---
 Libraries/LibHTML/CSS/Selector.h       | 1 +
 Libraries/LibHTML/Dump.cpp             | 3 +++
 Libraries/LibHTML/Parser/CSSParser.cpp | 6 +++++-
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/Libraries/LibHTML/CSS/Selector.h b/Libraries/LibHTML/CSS/Selector.h
index 1648a911f4..967b9e963d 100644
--- a/Libraries/LibHTML/CSS/Selector.h
+++ b/Libraries/LibHTML/CSS/Selector.h
@@ -18,6 +18,7 @@ public:
         enum class Relation {
             None,
             ImmediateChild,
+            Descendant,
         };
         Relation relation { Relation::None };
 
diff --git a/Libraries/LibHTML/Dump.cpp b/Libraries/LibHTML/Dump.cpp
index 0252c061b7..ae1d14e4f0 100644
--- a/Libraries/LibHTML/Dump.cpp
+++ b/Libraries/LibHTML/Dump.cpp
@@ -155,6 +155,9 @@ void dump_rule(const StyleRule& rule)
             case Selector::Component::Relation::ImmediateChild:
                 relation_description = "{ImmediateChild}";
                 break;
+            case Selector::Component::Relation::Descendant:
+                relation_description = "{Descendant}";
+                break;
             }
             dbgprintf("    %s:%s %s\n", type_description, component.value.characters(), relation_description);
         }
diff --git a/Libraries/LibHTML/Parser/CSSParser.cpp b/Libraries/LibHTML/Parser/CSSParser.cpp
index 61489b5d53..77df32ae2d 100644
--- a/Libraries/LibHTML/Parser/CSSParser.cpp
+++ b/Libraries/LibHTML/Parser/CSSParser.cpp
@@ -88,7 +88,7 @@ public:
     {
         consume_whitespace();
         Selector::Component::Type type;
-        Selector::Component::Relation relation = Selector::Component::Relation::None;
+        Selector::Component::Relation relation = Selector::Component::Relation::Descendant;
 
         if (peek() == '{')
             return {};
@@ -149,6 +149,10 @@ public:
                 break;
         }
 
+        if (components.is_empty())
+            return;
+        components.first().relation = Selector::Component::Relation::None;
+
         current_rule.selectors.append(Selector(move(components)));
     };