Changeset 286123 in webkit

Timestamp:

Nov 22, 2021 5:46:15 PM (8 months ago)

Author:

mmaxfield@apple.com

Message:

rem in media queries should be calculated using font-size:initial, not root element font-size
​https://bugs.webkit.org/show_bug.cgi?id=156684
<rdar://problem/25778616>

Reviewed by Antti Koivisto.

Source/WebCore:

The CSS spec says:

Relative units in media queries are based on the initial value, which means that units are never based on results of declarations.

Tests: imported/w3c/web-platform-tests/css/mediaqueries/relative-units-001.html

imported/w3c/web-platform-tests/css/mediaqueries/mq-calc-005.html

• css/MediaQueryEvaluator.cpp:

(WebCore::MediaQueryEvaluator::evaluate const):

LayoutTests:

• TestExpectations:

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/TestExpectations (modified) (1 diff)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/css/MediaQueryEvaluator.cpp (modified) (2 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2021-11-22  Myles C. Maxfield  <mmaxfield@apple.com>
+
+        rem in media queries should be calculated using font-size:initial, not root element font-size
+        https://bugs.webkit.org/show_bug.cgi?id=156684
+        <rdar://problem/25778616>
+
+        Reviewed by Antti Koivisto.
+
+        * TestExpectations:
+
 2021-11-22  Chris Fleizach  <cfleizach@apple.com>
 

trunk/LayoutTests/TestExpectations

@@ -1485 +1485 @@
 imported/w3c/web-platform-tests/css/mediaqueries/device-aspect-ratio-001.html [ Skip ]
 imported/w3c/web-platform-tests/css/mediaqueries/device-aspect-ratio-005.html [ Skip ]
-
-webkit.org/b/156684 imported/w3c/web-platform-tests/css/mediaqueries/relative-units-001.html [ ImageOnlyFailure ]
-webkit.org/b/156684 imported/w3c/web-platform-tests/css/mediaqueries/mq-calc-005.html [ ImageOnlyFailure ]
 
 # nth-child tests takes long time and Debug build sometimes timeouts because there are many test cases.

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-11-22  Myles C. Maxfield  <mmaxfield@apple.com>
+
+        rem in media queries should be calculated using font-size:initial, not root element font-size
+        https://bugs.webkit.org/show_bug.cgi?id=156684
+        <rdar://problem/25778616>
+
+        Reviewed by Antti Koivisto.
+
+        The CSS spec says:
+        > Relative units in media queries are based on the initial value, which means that units are never based on results of declarations.
+
+        Tests: imported/w3c/web-platform-tests/css/mediaqueries/relative-units-001.html
+               imported/w3c/web-platform-tests/css/mediaqueries/mq-calc-005.html
+
+        * css/MediaQueryEvaluator.cpp:
+        (WebCore::MediaQueryEvaluator::evaluate const):
+
 2021-11-22  Cameron McCormack  <heycam@apple.com>
 

trunk/Source/WebCore/css/MediaQueryEvaluator.cpp

@@ -50 +50 @@
 #include "RenderView.h"
 #include "Settings.h"
+#include "StyleFontSizeFunctions.h"
 #include "Theme.h"
 #include <wtf/HashMap.h>
@@ -927 +928 @@
     if (!document.documentElement())
         return false;
+
+    auto defaultStyle = RenderStyle::create();
+    auto fontDescription = defaultStyle.fontDescription();
+    auto size = Style::fontSizeForKeyword(CSSValueMedium, false, document);
+    fontDescription.setComputedSize(size);
+    fontDescription.setSpecifiedSize(size);
+    defaultStyle.setFontDescription(WTFMove(fontDescription));
+    defaultStyle.fontCascade().update();
     
     // Pass `nullptr` for `parentStyle` because we are in the context of a media query.
-    return function(expression.value(), { m_style, document.documentElement()->renderStyle(), nullptr, document.renderView(), 1, std::nullopt }, *frame, NoPrefix);
+    return function(expression.value(), { m_style, &defaultStyle, nullptr, document.renderView(), 1, std::nullopt }, *frame, NoPrefix);
 }