Invalid dir attribute should not affect directionality

https://bugs.webkit.org/show_bug.cgi?id=244439

Reviewed by Darin Adler and Alan Bujtas.

An invalid dir content attribute value should not have any effect on the directionality of text.

The issue was caused by WebKit adding unicode-bidi: embed style whenever there is dir content attribute
regardless of whether its value is valid or not.

New behavior of WebKit matches that of Gecko and Blink.

* LayoutTests/fast/css/default-bidi-css-rules-expected.txt: Rebaselined.
* LayoutTests/fast/css/default-bidi-css-rules.html: Ditto.
* LayoutTests/fast/dom/HTMLElement/attr-dir-invalid-expected.html: Added.
* LayoutTests/fast/dom/HTMLElement/attr-dir-invalid.html: Added.
* Source/WebCore/html/HTMLElement.cpp:
(WebCore::HTMLElement::collectPresentationalHintsForAttribute):

Canonical link: https://commits.webkit.org/253878@main

LayoutTests/fast/css/default-bidi-css-rules-expected.txt

@@ -9,7 +9,7 @@ PASS styleOf("div", {"dir":"rtl"}).unicodeBidi is "isolate"
 PASS styleOf("div", {"dir":"auto"}).direction is "ltr"
 PASS styleOf("div", {"dir":"auto"}).unicodeBidi is "isolate"
 PASS styleOf("div", {"dir":""}).direction is "ltr"
-PASS styleOf("div", {"dir":""}).unicodeBidi is "embed"
+PASS styleOf("div", {"dir":""}).unicodeBidi is "normal"
 PASS styleOf("span", {}).direction is "ltr"
 PASS styleOf("span", {}).unicodeBidi is "normal"
 PASS styleOf("span", {"dir":"ltr"}).direction is "ltr"
@@ -19,7 +19,7 @@ PASS styleOf("span", {"dir":"rtl"}).unicodeBidi is "isolate"
 PASS styleOf("span", {"dir":"auto"}).direction is "ltr"
 PASS styleOf("span", {"dir":"auto"}).unicodeBidi is "isolate"
 PASS styleOf("span", {"dir":""}).direction is "ltr"
-PASS styleOf("span", {"dir":""}).unicodeBidi is "embed"
+PASS styleOf("span", {"dir":""}).unicodeBidi is "normal"
 PASS styleOf("bdi", {}).direction is "ltr"
 PASS styleOf("bdi", {}).unicodeBidi is "isolate"
 PASS styleOf("bdi", {"dir":"ltr"}).direction is "ltr"
@@ -59,7 +59,7 @@ PASS styleOf("textarea", {"dir":"rtl"}).unicodeBidi is "isolate"
 PASS styleOf("textarea", {"dir":"auto"}).direction is "ltr"
 PASS styleOf("textarea", {"dir":"auto"}).unicodeBidi is "plaintext"
 PASS styleOf("textarea", {"dir":""}).direction is "ltr"
-PASS styleOf("textarea", {"dir":""}).unicodeBidi is "embed"
+PASS styleOf("textarea", {"dir":""}).unicodeBidi is "normal"
 PASS styleOf("pre", {}).direction is "ltr"
 PASS styleOf("pre", {}).unicodeBidi is "normal"
 PASS styleOf("pre", {"dir":"ltr"}).direction is "ltr"
@@ -69,7 +69,7 @@ PASS styleOf("pre", {"dir":"rtl"}).unicodeBidi is "isolate"
 PASS styleOf("pre", {"dir":"auto"}).direction is "ltr"
 PASS styleOf("pre", {"dir":"auto"}).unicodeBidi is "plaintext"
 PASS styleOf("pre", {"dir":""}).direction is "ltr"
-PASS styleOf("pre", {"dir":""}).unicodeBidi is "embed"
+PASS styleOf("pre", {"dir":""}).unicodeBidi is "normal"
 PASS successfullyParsed is true
 
 TEST COMPLETE

LayoutTests/fast/css/default-bidi-css-rules.html

@@ -24,13 +24,13 @@
     ['div', {'dir': 'ltr'}, 'ltr', 'isolate'],
     ['div', {'dir': 'rtl'}, 'rtl', 'isolate'],
     ['div', {'dir': 'auto'}, 'ltr', 'isolate'],
-    ['div', {'dir': ''}, 'ltr', 'embed'],
+    ['div', {'dir': ''}, 'ltr', 'normal'],
 
     ['span', {}, 'ltr', 'normal'],
     ['span', {'dir': 'ltr'}, 'ltr', 'isolate'],
     ['span', {'dir': 'rtl'}, 'rtl', 'isolate'],
     ['span', {'dir': 'auto'}, 'ltr', 'isolate'],
-    ['span', {'dir': ''}, 'ltr', 'embed'],
+    ['span', {'dir': ''}, 'ltr', 'normal'],
 
     ['bdi', {}, 'ltr', 'isolate'],
     ['bdi', {'dir': 'ltr'}, 'ltr', 'isolate'],
@@ -54,13 +54,13 @@
     ['textarea', {'dir': 'ltr'}, 'ltr', 'isolate'],
     ['textarea', {'dir': 'rtl'}, 'rtl', 'isolate'],
     ['textarea', {'dir': 'auto'}, 'ltr', 'plaintext'],
-    ['textarea', {'dir': ''}, 'ltr', 'embed'],
+    ['textarea', {'dir': ''}, 'ltr', 'normal'],
 
     ['pre', {}, 'ltr', 'normal'],
     ['pre', {'dir': 'ltr'}, 'ltr', 'isolate'],
     ['pre', {'dir': 'rtl'}, 'rtl', 'isolate'],
     ['pre', {'dir': 'auto'}, 'ltr', 'plaintext'],
-    ['pre', {'dir': ''}, 'ltr', 'embed'],
+    ['pre', {'dir': ''}, 'ltr', 'normal'],
 ].forEach(function (test) {
     shouldBe('styleOf("' + test[0] + '", ' + JSON.stringify(test[1]) + ').direction', '"' + test[2] + '"');
     container.innerHTML = '';

LayoutTests/fast/dom/HTMLElement/attr-dir-invalid-expected.html

@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html>
+<body>
+<div id="container" dir="auto">
+    <span id="rtl">&#1514;</span><span>b</span>
+    <span>a</span>
+</div>
+<style>
+#container { width: 100px; }
+</style>
+</body>
+</html>

LayoutTests/fast/dom/HTMLElement/attr-dir-invalid.html

@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<body>
+<div id="container" dir="auto">
+    <span id="rtl" dir="x">&#1514;</span>
+    <span>a</span>
+</div>
+<style>
+#container { width: 100px; }
+</style>
+<script>
+
+requestAnimationFrame(() => {
+    setTimeout(() => {
+        rtl.dir = 'x';
+        const span = document.createElement('span');
+        span.append('b');
+        rtl.after(span);
+        document.documentElement.className = '';
+    }, 0);
+});
+
+</script>
+</body>
+</html>

Source/WebCore/html/HTMLElement.cpp

@@ -218,16 +218,10 @@ void HTMLElement::collectPresentationalHintsForAttribute(const QualifiedName& na
     } else if (name == dirAttr) {
         if (equalLettersIgnoringASCIICase(value, "auto"_s))
             addPropertyToPresentationalHintStyle(style, CSSPropertyUnicodeBidi, unicodeBidiAttributeForDirAuto(*this));
-        else {
-            auto unicodeBidiValue = CSSValueEmbed;
-
-            if (equalLettersIgnoringASCIICase(value, "rtl"_s) || equalLettersIgnoringASCIICase(value, "ltr"_s)) {
-                addPropertyToPresentationalHintStyle(style, CSSPropertyDirection, value);
-                unicodeBidiValue = CSSValueIsolate;
-            } 
-
+        else if (equalLettersIgnoringASCIICase(value, "rtl"_s) || equalLettersIgnoringASCIICase(value, "ltr"_s)) {
+            addPropertyToPresentationalHintStyle(style, CSSPropertyDirection, value);
             if (!hasTagName(bdiTag) && !hasTagName(bdoTag) && !hasTagName(outputTag))
-                addPropertyToPresentationalHintStyle(style, CSSPropertyUnicodeBidi, unicodeBidiValue);
+                addPropertyToPresentationalHintStyle(style, CSSPropertyUnicodeBidi, CSSValueIsolate);
         }
     } else if (name.matches(XMLNames::langAttr))
         mapLanguageAttributeToLocale(value, style);