Fixed serialization due to broken longhands #129

CHANGELOG.md

@@ -1,3 +1,10 @@
+# 1.0.0
+
+Released on tbd.
+
+- Updated to use AngleSharp 1.0
+- Fixed issue when updating shorthands with invalid values (#129)
+
 # 0.17.0
 
 Released on Sunday, January 15 2023.

src/AngleSharp.Css.Tests/Library/StringRepresentation.cs

@@ -105,5 +105,17 @@ public void EscapePropertyNames_UnknownDeclaration_Issue120()
 
             Assert.AreEqual(css, generatedCss);
         }
+
+        [Test]
+        public void BorderWithEmptyPx_Issue129()
+        {
+            var html = "<div style=\"border-width:1px;border-right-width:px;\"></div>";
+            var dom = html.ToHtmlDocument(Configuration.Default.WithCss());
+            var div = dom.Body?.FirstElementChild;
+            var style = div.GetStyle();
+            var css = style.ToCss();
+
+            Assert.AreEqual("border-width: 1px", css);
+        }
     }
 }

src/AngleSharp.Css/Dom/Internal/CssStyleDeclaration.cs

@@ -134,7 +134,7 @@ private ICssProperty TryCreateShorthand(String shorthandName, IEnumerable<String
                         TryCreateShorthand(name, serialized, usedProperties, force) :
                         longhands.Where(m => m.Name == name).FirstOrDefault();
 
-                    if (property != null)
+                    if (property?.Value is not null)
                     {
                         usedProperties.Add(name);
                         count = count + 1;
@@ -318,8 +318,18 @@ internal void UpdateDeclarations(IEnumerable<ICssProperty> decls) =>
         private ICssProperty GetPropertyShorthand(String name) =>
             TryCreateShorthand(name, Enumerable.Empty<String>(), new List<String>(), true);
 
-        private ICssProperty CreateProperty(String propertyName) =>
-            GetProperty(propertyName) ?? _context.CreateProperty(propertyName);
+        private ICssProperty CreateProperty(String propertyName)
+        {
+            var newProperty = _context.CreateProperty(propertyName);
+            var existing = GetProperty(propertyName);
+
+            if (existing is not null)
+            {
+                newProperty.RawValue = existing.RawValue;
+            }
+
+            return newProperty;
+        }
 
         private void SetProperty(ICssProperty property)
         {