From 338282f74d3f9a2421db821f673be32c4e7eed38 Mon Sep 17 00:00:00 2001
From: Sam Atkins <sam@ladybird.org>
Date: Fri, 16 May 2025 20:15:07 +0100
Subject: [PATCH] LibWeb/CSS: Treat x resolution unit separately from dppx

Tests show that we need to preserve whether x or dppx units were used,
so the simplest way is to treat them separately.
---
 Libraries/LibWeb/CSS/Resolution.cpp                  | 12 ++++++++----
 Libraries/LibWeb/CSS/Resolution.h                    |  1 +
 .../css/mediaqueries/match-media-parsing.txt         | 10 +++++-----
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/Libraries/LibWeb/CSS/Resolution.cpp b/Libraries/LibWeb/CSS/Resolution.cpp
index 4a16d554994..17ee98db2fb 100644
--- a/Libraries/LibWeb/CSS/Resolution.cpp
+++ b/Libraries/LibWeb/CSS/Resolution.cpp
@@ -35,6 +35,7 @@ double Resolution::to_dots_per_pixel() const
     case Type::Dpcm:
         return m_value / (96.0 / 2.54); // 1cm = 96px/2.54
     case Type::Dppx:
+    case Type::X:
         return m_value;
     }
     VERIFY_NOT_REACHED();
@@ -49,19 +50,22 @@ StringView Resolution::unit_name() const
         return "dpcm"sv;
     case Type::Dppx:
         return "dppx"sv;
+    case Type::X:
+        return "x"sv;
     }
     VERIFY_NOT_REACHED();
 }
 
 Optional<Resolution::Type> Resolution::unit_from_name(StringView name)
 {
-    if (name.equals_ignoring_ascii_case("dpi"sv)) {
+    if (name.equals_ignoring_ascii_case("dpi"sv))
         return Type::Dpi;
-    } else if (name.equals_ignoring_ascii_case("dpcm"sv)) {
+    if (name.equals_ignoring_ascii_case("dpcm"sv))
         return Type::Dpcm;
-    } else if (name.equals_ignoring_ascii_case("dppx"sv) || name.equals_ignoring_ascii_case("x"sv)) {
+    if (name.equals_ignoring_ascii_case("dppx"sv))
         return Type::Dppx;
-    }
+    if (name.equals_ignoring_ascii_case("x"sv))
+        return Type::X;
     return {};
 }
 
diff --git a/Libraries/LibWeb/CSS/Resolution.h b/Libraries/LibWeb/CSS/Resolution.h
index f62012b6107..ef80fd8b5c7 100644
--- a/Libraries/LibWeb/CSS/Resolution.h
+++ b/Libraries/LibWeb/CSS/Resolution.h
@@ -17,6 +17,7 @@ public:
         Dpi,
         Dpcm,
         Dppx,
+        X,
     };
 
     static Optional<Type> unit_from_name(StringView);
diff --git a/Tests/LibWeb/Text/expected/wpt-import/css/mediaqueries/match-media-parsing.txt b/Tests/LibWeb/Text/expected/wpt-import/css/mediaqueries/match-media-parsing.txt
index 9d4b9a5453d..066feea908f 100644
--- a/Tests/LibWeb/Text/expected/wpt-import/css/mediaqueries/match-media-parsing.txt
+++ b/Tests/LibWeb/Text/expected/wpt-import/css/mediaqueries/match-media-parsing.txt
@@ -2,8 +2,8 @@ Harness status: OK
 
 Found 34 tests
 
-27 Pass
-7 Fail
+30 Pass
+4 Fail
 Pass	Test parsing '' with matchMedia
 Pass	Test parsing ' ' with matchMedia
 Pass	Test parsing 'all' with matchMedia
@@ -25,11 +25,11 @@ Pass	Test parsing ' , ' with matchMedia
 Fail	Test parsing ',,' with matchMedia
 Pass	Test parsing '  ,  ,  ' with matchMedia
 Fail	Test parsing ' foo,' with matchMedia
-Fail	Test parsing '(min-resolution: 1x)' with matchMedia
+Pass	Test parsing '(min-resolution: 1x)' with matchMedia
 Pass	Test parsing '(min-resolution: calc(1x))' with matchMedia
-Fail	Test parsing '(resolution: 2x)' with matchMedia
+Pass	Test parsing '(resolution: 2x)' with matchMedia
 Pass	Test parsing '(resolution: calc(2x))' with matchMedia
-Fail	Test parsing '(max-resolution: 7x)' with matchMedia
+Pass	Test parsing '(max-resolution: 7x)' with matchMedia
 Pass	Test parsing '(max-resolution: calc(7x))' with matchMedia
 Pass	Test parsing '(resolution: 2dppx)' with matchMedia
 Pass	Test parsing '(resolution: 600dpi)' with matchMedia