From ec87545774c819cde014eed0cac83fe007fa6a4d Mon Sep 17 00:00:00 2001
From: "Panashe M. Fundira" <fundirap@gmail.com>
Date: Sat, 11 Mar 2017 20:50:41 -0500
Subject: [PATCH] PropertyDeclaration with CSSWideKeyword is parsed

Addresses #15401

The desired result is for `CSSWideKeyword`s to return false (they are
parsed) and other Custom declaration values to return true (they are unparsed).
---
 .../style/properties/properties.mako.rs       |  4 +++-
 tests/unit/style/properties/serialization.rs  | 21 +++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index 5dca7bee0cc..4b360fea1d2 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -1174,7 +1174,9 @@ impl PropertyDeclaration {
     pub fn value_is_unparsed(&self) -> bool {
       match *self {
           PropertyDeclaration::WithVariables(..) => true,
-          PropertyDeclaration::Custom(..) => true,
+          PropertyDeclaration::Custom(_, ref value) => {
+            !matches!(value.borrow(), DeclaredValue::CSSWideKeyword(..))
+          }
           _ => false,
       }
     }
diff --git a/tests/unit/style/properties/serialization.rs b/tests/unit/style/properties/serialization.rs
index 1eb5b75feb8..a9eabc1be8c 100644
--- a/tests/unit/style/properties/serialization.rs
+++ b/tests/unit/style/properties/serialization.rs
@@ -1124,4 +1124,25 @@ mod shorthand_serialization {
             assert_eq!(serialization, block_text);
         }
     }
+
+    mod keywords {
+        pub use super::*;
+        #[test]
+        fn css_wide_keywords_should_be_parsed() {
+            let block_text = "--a:inherit;";
+            let block = parse_declaration_block(block_text);
+
+            let serialization = block.to_css_string();
+            assert_eq!(serialization, "--a: inherit;");
+        }
+
+        #[test]
+        fn non_keyword_custom_property_should_be_unparsed() {
+            let block_text = "--main-color: #06c;";
+            let block = parse_declaration_block(block_text);
+
+            let serialization = block.to_css_string();
+            assert_eq!(serialization, block_text);
+        }
+    }
 }