Don't update OverScroller fling state if no time has passed since start

If no time has passed when we try to update fling state, skip the
update computation since there is nothing to do.

Fixes a bug where we could return NaN from
OverScroller#getCurrentVelocity.

Bug 17700698

Change-Id: I65042d4d26a29593f66781b58456c2d1e85381c6

1 files changed, 4 insertions, 0 deletions

diff --git a/core/java/android/widget/OverScroller.java b/core/java/android/widget/OverScroller.java
index 7b3dd31..a40d4f8 100644
--- a/core/java/android/widget/OverScroller.java
+++ b/core/java/android/widget/OverScroller.java
@@ -904,6 +904,10 @@ public class OverScroller {
             final long time = AnimationUtils.currentAnimationTimeMillis();
             final long currentTime = time - mStartTime;
 
+            if (currentTime == 0) {
+                // Skip work but report that we're still going if we have a nonzero duration.
+                return mDuration > 0;
+            }
             if (currentTime > mDuration) {
                 return false;
             }