Bug 506096: In SVG Animation (SMIL), make sure to visit the underlying base value for first half of duration, in discrete-mode "to" animations. r+sr=roc

content/smil/nsSMILAnimationFunction.cpp

@@ -407,9 +407,13 @@ nsSMILAnimationFunction::InterpolateResult(const nsSMILValueArray& aValues,
 
   // Handle CALC_DISCRETE separately, because it's simple.
   if (GetCalcMode() == CALC_DISCRETE) {
-    PRUint32 index = IsToAnimation() ? 0 :
-      (PRUint32) floor(simpleProgress * (aValues.Length()));
-    aResult = aValues[index];
+    if (IsToAnimation()) {
+      // Two discrete values: our base value, and the val in our array
+      aResult = (simpleProgress < 0.5f) ? aBaseValue : aValues[0];
+    } else {
+      PRUint32 index = (PRUint32) floor(simpleProgress * (aValues.Length()));
+      aResult = aValues[index];
+    }
     return NS_OK;
   }
 

layout/reftests/svg/smil/reftest.list

@@ -48,6 +48,11 @@ include pause/reftest.list
 == anim-discrete-sum-none-1.svg    anim-standard-ref.svg
 == anim-discrete-sum-sum-1.svg     anim-standard-ref.svg
 
+== anim-discrete-to-1.svg          anim-standard-ref.svg
+== anim-discrete-to-2.svg          anim-standard-ref.svg
+== anim-discrete-to-3.svg          anim-standard-ref.svg
+== anim-discrete-to-4.svg          anim-standard-ref.svg
+
 fails == anim-fillcolor-1.svg      anim-standard-ref.svg # color support
 fails == anim-fillopacity-1.svg anim-standard-ref.svg    # non-length-numeric values support