Auto merge of #15226 - dashed:gh-15208, r=emilio

Fix text-overflow serialization.

Fixes https://github.com/servo/servo/issues/15208

- [x] **More tests pending PR review.**
- [x] **Correct placement of unit test**

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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #15208 (github issue number if applicable).

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- [x] There are tests for these changes OR
- [ ] These changes do not require tests because _____

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components/style/properties/longhand/text.mako.rs

@@ -18,6 +18,7 @@
     use style_traits::ToCss;
     use values::NoViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
+    use cssparser;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
     impl NoViewportPercentage for SpecifiedValue {}
@@ -75,7 +76,9 @@
             match *self {
                 Side::Clip => dest.write_str("clip"),
                 Side::Ellipsis => dest.write_str("ellipsis"),
-                Side::String(ref s) => dest.write_str(s)
+                Side::String(ref s) => {
+                    cssparser::serialize_string(s, dest)
+                }
             }
         }
     }

tests/unit/style/parsing/mod.rs

@@ -78,3 +78,4 @@ mod mask;
 mod position;
 mod selectors;
 mod supports;
+mod text_overflow;

tests/unit/style/parsing/text_overflow.rs

@@ -0,0 +1,24 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use cssparser::Parser;
+use media_queries::CSSErrorReporterTest;
+use style::parser::ParserContext;
+use style::stylesheets::Origin;
+use style_traits::ToCss;
+
+#[test]
+fn test_text_overflow() {
+    use style::properties::longhands::text_overflow;
+
+    assert_roundtrip_with_context!(text_overflow::parse, r#"clip"#);
+    assert_roundtrip_with_context!(text_overflow::parse, r#"ellipsis"#);
+    assert_roundtrip_with_context!(text_overflow::parse, r#"clip ellipsis"#);
+    assert_roundtrip_with_context!(text_overflow::parse, r#""x""#);
+    assert_roundtrip_with_context!(text_overflow::parse, r#"'x'"#, r#""x""#);
+    assert_roundtrip_with_context!(text_overflow::parse, r#"clip "x""#);
+    assert_roundtrip_with_context!(text_overflow::parse, r#""x" clip"#);
+    assert_roundtrip_with_context!(text_overflow::parse, r#""x" "y""#);
+
+}