Gracefully handle zero duration curves in CCActiveAnimation

cc/CCActiveAnimation.cpp

Index: cc/CCActiveAnimation.cpp
diff --git a/cc/CCActiveAnimation.cpp b/cc/CCActiveAnimation.cpp
index f09209e1a7c71eb7ca89e4fa9524d2aeed21bc29..36c7c2b1583773539defba7a586bdd8c9c371b9d 100644
--- a/cc/CCActiveAnimation.cpp
+++ b/cc/CCActiveAnimation.cpp
@@ -154,6 +154,10 @@ double CCActiveAnimation::trimTimeToCurrentIteration(double monotonicTime) const
     if (!m_iterations)
         return 0;
 
+    // Don't attempt to trim if we have no duration.
+    if (m_curve->duration() <= 0)
+        return 0;
+
     // If less than an iteration duration, just return trimmed.
     if (trimmed < m_curve->duration())
         return trimmed;