css background-size property: do not use CSS_UNKNOWN type to map internally

'auto' value as its serialization return a null string.

khtml/css/cssparser.cpp

@@ -1819,7 +1819,7 @@ CSSValueImpl* CSSParser::parseBackgroundSize()
         return new CSSPrimitiveValueImpl(value->id);
 
     if (value->id == CSS_VAL_AUTO)
-        parsedValue1 = new CSSPrimitiveValueImpl(0, CSSPrimitiveValue::CSS_UNKNOWN);
+        parsedValue1 = new CSSPrimitiveValueImpl(CSS_VAL_AUTO);
     else {
         if (!validUnit(value, FLength|FPercent|FNonNeg, strict))
             return 0;
@@ -1829,7 +1829,7 @@ CSSValueImpl* CSSParser::parseBackgroundSize()
     CSSPrimitiveValueImpl* parsedValue2;
     if ((value = valueList->next())) {
         if (value->id == CSS_VAL_AUTO)
-            parsedValue2 = new CSSPrimitiveValueImpl(0, CSSPrimitiveValue::CSS_UNKNOWN);
+            parsedValue2 = new CSSPrimitiveValueImpl(CSS_VAL_AUTO);
         else {
             if (!validUnit(value, FLength|FPercent|FNonNeg, strict)) {
                 delete parsedValue1;
@@ -1838,7 +1838,7 @@ CSSValueImpl* CSSParser::parseBackgroundSize()
             parsedValue2 = new CSSPrimitiveValueImpl(value->fValue, (CSSPrimitiveValue::UnitTypes)value->unit);
         }
     } else {
-        parsedValue2 = new CSSPrimitiveValueImpl(0, CSSPrimitiveValue::CSS_UNKNOWN);
+        parsedValue2 = new CSSPrimitiveValueImpl(CSS_VAL_AUTO);
     }
 
     PairImpl* pair = new PairImpl(parsedValue1, parsedValue2);

khtml/css/cssstyleselector.cpp

@@ -4443,26 +4443,32 @@ void CSSStyleSelector::mapBackgroundSize(BackgroundLayer* layer, CSSValueImpl* v
         return;
 
     Length firstLength, secondLength;
-    int firstType = first->primitiveType();
-    int secondType = second->primitiveType();
 
-    if (firstType == CSSPrimitiveValue::CSS_UNKNOWN)
+    if (first->getIdent() == CSS_VAL_AUTO) {
         firstLength = Length(Auto);
-    else if (firstType > CSSPrimitiveValue::CSS_PERCENTAGE && firstType < CSSPrimitiveValue::CSS_DEG)
+    } else {
+        const unsigned short firstType = first->primitiveType();
+        if (firstType > CSSPrimitiveValue::CSS_PERCENTAGE && firstType < CSSPrimitiveValue::CSS_DEG) {
             firstLength = Length(first->computeLength(style, logicalDpiY), Fixed);
-    else if (firstType == CSSPrimitiveValue::CSS_PERCENTAGE)
+        } else if (firstType == CSSPrimitiveValue::CSS_PERCENTAGE) {
             firstLength = Length(first->floatValue(CSSPrimitiveValue::CSS_PERCENTAGE), Percent);
-    else
+        } else {
             return;
+        }
+    }
 
-    if (secondType == CSSPrimitiveValue::CSS_UNKNOWN)
+    if (second->getIdent() == CSS_VAL_AUTO) {
         secondLength = Length(Auto);
-    else if (secondType > CSSPrimitiveValue::CSS_PERCENTAGE && secondType < CSSPrimitiveValue::CSS_DEG)
+    } else {
+        const unsigned short secondType = second->primitiveType();
+        if (secondType > CSSPrimitiveValue::CSS_PERCENTAGE && secondType < CSSPrimitiveValue::CSS_DEG) {
             secondLength = Length(second->computeLength(style, logicalDpiY), Fixed);
-    else if (secondType == CSSPrimitiveValue::CSS_PERCENTAGE)
+        } else if (secondType == CSSPrimitiveValue::CSS_PERCENTAGE) {
             secondLength = Length(second->floatValue(CSSPrimitiveValue::CSS_PERCENTAGE), Percent);
-    else
+        } else {
             return;
+        }
+    }
 
     b.width = firstLength;
     b.height = secondLength;