From 4dd841a0366cef8bb08a796df51045e8737af209 Mon Sep 17 00:00:00 2001
From: Anurag Kalia <anurag.kalia@outlook.com>
Date: Mon, 17 Oct 2022 09:28:44 +0000
Subject: [PATCH] style: Make vertical writing mode (left/right) in
 text-emphasis-position optional

Differential Revision: https://phabricator.services.mozilla.com/D158399
---
 .../longhands/inherited_text.mako.rs          |  4 ++--
 components/style/values/specified/box.rs      |  2 +-
 components/style/values/specified/text.rs     | 20 +++++++++++--------
 components/style_derive/parse.rs              |  2 +-
 4 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/components/style/properties/longhands/inherited_text.mako.rs b/components/style/properties/longhands/inherited_text.mako.rs
index 627822994bc..541d102a1de 100644
--- a/components/style/properties/longhands/inherited_text.mako.rs
+++ b/components/style/properties/longhands/inherited_text.mako.rs
@@ -221,9 +221,9 @@ ${helpers.predefined_type(
 ${helpers.predefined_type(
     "text-emphasis-position",
     "TextEmphasisPosition",
-    "computed::TextEmphasisPosition::DEFAULT",
+    "computed::TextEmphasisPosition::OVER",
     engines="gecko",
-    initial_specified_value="specified::TextEmphasisPosition::DEFAULT",
+    initial_specified_value="specified::TextEmphasisPosition::OVER",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-text-decor/#propdef-text-emphasis-position",
 )}
diff --git a/components/style/values/specified/box.rs b/components/style/values/specified/box.rs
index c0e2756c54e..0faf01bc778 100644
--- a/components/style/values/specified/box.rs
+++ b/components/style/values/specified/box.rs
@@ -2242,7 +2242,7 @@ bitflags! {
 
 impl ScrollbarGutter {
     #[inline]
-    fn has_stable(self) -> bool {
+    fn has_stable(&self) -> bool {
         self.intersects(Self::STABLE)
     }
 }
diff --git a/components/style/values/specified/text.rs b/components/style/values/specified/text.rs
index 02711ba61e9..5f21c774372 100644
--- a/components/style/values/specified/text.rs
+++ b/components/style/values/specified/text.rs
@@ -774,7 +774,7 @@ impl Parse for TextEmphasisStyle {
 bitflags! {
     #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem, Parse, ToCss)]
     #[repr(C)]
-    #[css(bitflags(mixed="over,under,left,right", validate_mixed="Self::is_valid"))]
+    #[css(bitflags(mixed="over,under,left,right", validate_mixed="Self::validate_and_simplify"))]
     /// Values for text-emphasis-position:
     /// <https://drafts.csswg.org/css-text-decor/#text-emphasis-position-property>
     pub struct TextEmphasisPosition: u8 {
@@ -786,17 +786,21 @@ bitflags! {
         const LEFT = 1 << 2;
         /// Draws marks to the right of the text in vertical writing mode.
         const RIGHT = 1 << 3;
-        /// Returns the initial value of `text-emphasis-position`
-        const DEFAULT = Self::OVER.bits | Self::RIGHT.bits;
-        /// Non-standard behavior: Intelligent default for zh locale
-        const DEFAULT_ZH = Self::UNDER.bits | Self::RIGHT.bits;
     }
 }
 
 impl TextEmphasisPosition {
-    fn is_valid(self) -> bool {
-        return self.intersects(Self::LEFT) != self.intersects(Self::RIGHT) &&
-            self.intersects(Self::OVER) != self.intersects(Self::UNDER);
+    fn validate_and_simplify(&mut self) -> bool {
+        if self.intersects(Self::OVER) == self.intersects(Self::UNDER) {
+            return false;
+        }
+
+        if self.intersects(Self::LEFT) {
+            return !self.intersects(Self::RIGHT);
+        }
+
+        self.remove(Self::RIGHT); // Right is the default
+        true
     }
 }
 
diff --git a/components/style_derive/parse.rs b/components/style_derive/parse.rs
index 54982c3dec1..d73e1993c89 100644
--- a/components/style_derive/parse.rs
+++ b/components/style_derive/parse.rs
@@ -47,7 +47,7 @@ fn parse_bitflags(bitflags: &CssBitflagAttrs) -> TokenStream {
     let mut validate_condition = quote! { !result.is_empty() };
     if let Some(ref function) = bitflags.validate_mixed {
         validate_condition.append_all(quote! {
-            && #function(result)
+            && #function(&mut result)
         });
     }