From 4dc2bd3df04369fd4f6284afdaea33cacbb3af43 Mon Sep 17 00:00:00 2001
From: martinfalisse <martinmotteditfalisse@gmail.com>
Date: Sat, 1 Oct 2022 13:06:45 +0200
Subject: [PATCH] LibWeb: Handle different span properties for
 GridTrackPlacement parsing

These changes improve the parsing of the span property, including
handling negative values for the span (defaults to 1), as well as when
no number is passed (also defaults to 1).
---
 .../Libraries/LibWeb/CSS/Parser/Parser.cpp    | 39 +++++++++++++++----
 1 file changed, 31 insertions(+), 8 deletions(-)

diff --git a/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp b/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
index 287726e55e..6885994c70 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
+++ b/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
@@ -5452,19 +5452,29 @@ RefPtr<StyleValue> Parser::parse_grid_track_placement(Vector<ComponentValue> con
     if (!tokens.has_next_token()) {
         if (current_token.is(Token::Type::Ident) && current_token.ident().equals_ignoring_case("auto"sv))
             return GridTrackPlacementStyleValue::create(CSS::GridTrackPlacement());
+        // https://drafts.csswg.org/css-grid/#grid-placement-span-int
+        // If the <integer> is omitted, it defaults to 1.
+        if (current_token.is(Token::Type::Ident) && current_token.ident().equals_ignoring_case("span"sv))
+            return GridTrackPlacementStyleValue::create(CSS::GridTrackPlacement(1, true));
         if (current_token.is(Token::Type::Number) && current_token.number().is_integer())
             return GridTrackPlacementStyleValue::create(CSS::GridTrackPlacement(static_cast<int>(current_token.number_value())));
         return {};
     }
 
-    auto has_span = false;
+    auto is_span = false;
     if (current_token.is(Token::Type::Ident) && current_token.ident().equals_ignoring_case("span"sv)) {
-        has_span = true;
+        is_span = true;
         tokens.skip_whitespace();
         current_token = tokens.next_token().token();
     }
-    if (current_token.is(Token::Type::Number) && current_token.number().is_integer() && !tokens.has_next_token())
-        return GridTrackPlacementStyleValue::create(CSS::GridTrackPlacement(static_cast<int>(current_token.number_value()), has_span));
+
+    if (current_token.is(Token::Type::Number) && current_token.number().is_integer() && !tokens.has_next_token()) {
+        // https://drafts.csswg.org/css-grid/#grid-placement-span-int
+        // Negative integers or zero are invalid.
+        if (is_span && static_cast<int>(current_token.number_value()) < 1)
+            return GridTrackPlacementStyleValue::create(CSS::GridTrackPlacement(1, is_span));
+        return GridTrackPlacementStyleValue::create(CSS::GridTrackPlacement(static_cast<int>(current_token.number_value()), is_span));
+    }
     return {};
 }
 
@@ -5476,20 +5486,33 @@ RefPtr<StyleValue> Parser::parse_grid_track_placement_shorthand_value(Vector<Com
     if (!tokens.has_next_token()) {
         if (current_token.is(Token::Type::Ident) && current_token.ident().equals_ignoring_case("auto"sv))
             return GridTrackPlacementShorthandStyleValue::create(CSS::GridTrackPlacement::make_auto());
+        // https://drafts.csswg.org/css-grid/#grid-placement-span-int
+        // If the <integer> is omitted, it defaults to 1.
+        if (current_token.is(Token::Type::Ident) && current_token.ident().equals_ignoring_case("span"sv))
+            return GridTrackPlacementShorthandStyleValue::create(CSS::GridTrackPlacement(1, true));
         if (current_token.is(Token::Type::Number) && current_token.number().is_integer())
             return GridTrackPlacementShorthandStyleValue::create(CSS::GridTrackPlacement(current_token.number_value()));
         return {};
     }
 
     auto calculate_grid_track_placement = [](auto& current_token, auto& tokens) -> CSS::GridTrackPlacement {
-        auto has_span = false;
+        auto is_span = false;
         if (current_token.is(Token::Type::Ident) && current_token.ident().equals_ignoring_case("span"sv)) {
-            has_span = true;
+            is_span = true;
             tokens.skip_whitespace();
             current_token = tokens.next_token().token();
         }
-        if (current_token.is(Token::Type::Number) && current_token.number().is_integer())
-            return CSS::GridTrackPlacement(static_cast<int>(current_token.number_value()), has_span);
+        if (current_token.is(Token::Type::Number) && current_token.number().is_integer()) {
+            // https://drafts.csswg.org/css-grid/#grid-placement-span-int
+            // Negative integers or zero are invalid.
+            if (is_span && static_cast<int>(current_token.number_value()) < 1)
+                return CSS::GridTrackPlacement(1, true);
+            return CSS::GridTrackPlacement(static_cast<int>(current_token.number_value()), is_span);
+        }
+        // https://drafts.csswg.org/css-grid/#grid-placement-span-int
+        // If the <integer> is omitted, it defaults to 1.
+        if (is_span && current_token.is(Token::Type::Delim) && current_token.delim() == "/"sv)
+            return CSS::GridTrackPlacement(1, true);
         return CSS::GridTrackPlacement();
     };