Fix computed values of 'font-weight' to report integers for bold (like for normal) and to report usable values for bolder/lighter. (Bug 173331, Bug 77882) r=bzbarsky

layout/style/nsComputedDOMStyle.cpp

@@ -1257,14 +1257,17 @@ nsComputedDOMStyle::GetFontWeight(nsIDOMCSSValue** aValue)
 
   const nsStyleFont* font = GetStyleFont();
 
-  // XXX This doesn't deal with bolder/lighter very well.
-  const nsCSSKeyword enum_weight =
-    nsCSSProps::ValueToKeywordEnum(font->mFont.weight,
-                                   nsCSSProps::kFontWeightKTable);
-  if (enum_weight != eCSSKeyword_UNKNOWN) {
-    val->SetIdent(enum_weight);
-  } else {
+  PRUint16 weight = font->mFont.weight;
+  if (weight % 100 == 0) {
     val->SetNumber(font->mFont.weight);
+  } else if (weight % 100 > 50) {
+    // FIXME: This doesn't represent the full range of computed values,
+    // but at least it's legal CSS.
+    val->SetIdent(eCSSKeyword_lighter);
+  } else {
+    // FIXME: This doesn't represent the full range of computed values,
+    // but at least it's legal CSS.
+    val->SetIdent(eCSSKeyword_bolder);
   }
 
   return CallQueryInterface(val, aValue);

layout/style/test/property_database.js

@@ -1361,7 +1361,7 @@ var gCSSProperties = {
 		inherited: true,
 		type: CSS_TYPE_LONGHAND,
 		initial_values: [ "normal", "400" ],
-		other_values: [ "bold", "100", "200", "300", "500", "600", "700", "800", "900" ],
+		other_values: [ "bold", "100", "200", "300", "500", "600", "700", "800", "900", "bolder", "lighter" ],
 		invalid_values: [ "107", "399", "401", "699", "710" ]
 	},
 	"height": {

layout/style/test/test_transitions_per_property.html

@@ -460,21 +460,20 @@ function test_font_weight(prop) {
 
   div.style.setProperty("-moz-transition-property", "none", "");
   div.style.setProperty(prop, "normal", "");
-  is(cs.getPropertyValue(prop), "normal",
+  is(cs.getPropertyValue(prop), "400",
      "font-weight property " + prop + ": computed value before transition");
   div.style.setProperty("-moz-transition-property", prop, "");
   div.style.setProperty(prop, "900", "");
   is(cs.getPropertyValue(prop), "600",
      "font-weight property " + prop + ": interpolation of font-weights");
   div.style.setProperty(prop, "lighter", "");
-  // We currently get 399; mark this as todo.
-  todo_is(cs.getPropertyValue(prop), "lighter",
+  is(cs.getPropertyValue(prop), "lighter",
      "font-weight property " + prop + ": can't interpolate bolder/lighter");
   div.style.setProperty(prop, "700", "");
-  is(cs.getPropertyValue(prop), "bold",
+  is(cs.getPropertyValue(prop), "700",
      "font-weight property " + prop + ": computed value before transition");
   div.style.setProperty(prop, "100", "");
-  is(cs.getPropertyValue(prop), "normal",
+  is(cs.getPropertyValue(prop), "400",
      "font-weight property " + prop + ": interpolation of font-weights");
 }