From 11e2dbb555ea42c926d6a7824c93c2581f891ec8 Mon Sep 17 00:00:00 2001
From: Sam Atkins <sam@ladybird.org>
Date: Thu, 17 Jul 2025 10:50:35 +0100
Subject: [PATCH] LibWeb/CSS: Support `text-justify: distribute` legacy value
 alias

...for `text-justify: inter-character`.

We previously had this mapped in Enums.json, but the behaviour is
different: `a=b` in Enums.json keeps `a` around but makes it behave the
same as `b`. A legacy name alias is instead expected to replace `a`
with `b`, so we have to do that separately.
---
 Libraries/LibWeb/CSS/Enums.json                    |  3 +--
 Libraries/LibWeb/CSS/Parser/PropertyParsing.cpp    | 11 +++++++++++
 Libraries/LibWeb/CSS/Properties.json               |  3 +++
 .../text-justify/distribute-alias.tentative.txt    |  6 ++++++
 .../text-justify/distribute-alias.tentative.html   | 14 ++++++++++++++
 5 files changed, 35 insertions(+), 2 deletions(-)
 create mode 100644 Tests/LibWeb/Text/expected/wpt-import/css/css-text/text-justify/distribute-alias.tentative.txt
 create mode 100644 Tests/LibWeb/Text/input/wpt-import/css/css-text/text-justify/distribute-alias.tentative.html

diff --git a/Libraries/LibWeb/CSS/Enums.json b/Libraries/LibWeb/CSS/Enums.json
index 38748f94332..b347cd0ad2f 100644
--- a/Libraries/LibWeb/CSS/Enums.json
+++ b/Libraries/LibWeb/CSS/Enums.json
@@ -638,8 +638,7 @@
     "auto",
     "none",
     "inter-word",
-    "inter-character",
-    "distribute=inter-character"
+    "inter-character"
   ],
   "text-overflow": [
     "clip",
diff --git a/Libraries/LibWeb/CSS/Parser/PropertyParsing.cpp b/Libraries/LibWeb/CSS/Parser/PropertyParsing.cpp
index 0b824dbe434..017ae22d660 100644
--- a/Libraries/LibWeb/CSS/Parser/PropertyParsing.cpp
+++ b/Libraries/LibWeb/CSS/Parser/PropertyParsing.cpp
@@ -724,6 +724,17 @@ Parser::ParseErrorOr<NonnullRefPtr<CSSStyleValue const>> Parser::parse_css_value
         if (auto parsed_value = parse_text_decoration_line_value(tokens); parsed_value && !tokens.has_next_token())
             return parsed_value.release_nonnull();
         return ParseError::SyntaxError;
+    case PropertyID::TextJustify:
+        if (auto parsed_value = parse_css_value_for_property(property_id, tokens); parsed_value && !tokens.has_next_token()) {
+            // https://drafts.csswg.org/css-text-3/#valdef-text-justify-distribute
+            // For legacy reasons, UAs must also support the alternate keyword distribute which must compute to
+            // inter-character, thus having the exact same meaning and behavior. UAs may treat this as a legacy value alias.
+            // FIXME: Figure out a generic way of supporting legacy value aliases.
+            if (parsed_value->to_keyword() == Keyword::Distribute)
+                return CSSKeywordValue::create(Keyword::InterCharacter);
+            return parsed_value.release_nonnull();
+        }
+        return ParseError::SyntaxError;
     case PropertyID::TextShadow:
         if (auto parsed_value = parse_shadow_value(tokens, AllowInsetKeyword::No); parsed_value && !tokens.has_next_token())
             return parsed_value.release_nonnull();
diff --git a/Libraries/LibWeb/CSS/Properties.json b/Libraries/LibWeb/CSS/Properties.json
index d3e5e5e5904..a7f5bc49f04 100644
--- a/Libraries/LibWeb/CSS/Properties.json
+++ b/Libraries/LibWeb/CSS/Properties.json
@@ -3158,6 +3158,9 @@
     "initial": "auto",
     "valid-types": [
       "text-justify"
+    ],
+    "valid-identifiers": [
+      "distribute"
     ]
   },
   "text-overflow": {
diff --git a/Tests/LibWeb/Text/expected/wpt-import/css/css-text/text-justify/distribute-alias.tentative.txt b/Tests/LibWeb/Text/expected/wpt-import/css/css-text/text-justify/distribute-alias.tentative.txt
new file mode 100644
index 00000000000..2183b6327f3
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/wpt-import/css/css-text/text-justify/distribute-alias.tentative.txt
@@ -0,0 +1,6 @@
+Harness status: OK
+
+Found 1 tests
+
+1 Pass
+Pass	text-justify: distribute is a parse-time alias of inter-character
\ No newline at end of file
diff --git a/Tests/LibWeb/Text/input/wpt-import/css/css-text/text-justify/distribute-alias.tentative.html b/Tests/LibWeb/Text/input/wpt-import/css/css-text/text-justify/distribute-alias.tentative.html
new file mode 100644
index 00000000000..2b157246889
--- /dev/null
+++ b/Tests/LibWeb/Text/input/wpt-import/css/css-text/text-justify/distribute-alias.tentative.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<link rel=author href="mailto:emilio@crisal.io" title="Emilio Cobos Álvarez">
+<link rel=author href="https://mozilla.org" title="Mozilla">
+<link rel=help href="https://github.com/w3c/csswg-drafts/issues/6156">
+<title>text-justify: distribute is a parse-time alias of inter-character</title>
+<script src="../../../resources/testharness.js"></script>
+<script src="../../../resources/testharnessreport.js"></script>
+<script>
+  test(function() {
+    let style = document.createElement("div").style;
+    style.textJustify = "distribute";
+    assert_equals(style.textJustify, "inter-character");
+  });
+</script>