[libgdx] Apply left over time additively to track time of delayed TrackEntry. See #1504.

spine-libgdx/spine-libgdx/src/com/esotericsoftware/spine/AnimationState.java

@@ -37,7 +37,6 @@ import com.badlogic.gdx.utils.IntArray;
 import com.badlogic.gdx.utils.IntSet;
 import com.badlogic.gdx.utils.Pool;
 import com.badlogic.gdx.utils.Pool.Poolable;
-
 import com.esotericsoftware.spine.Animation.AttachmentTimeline;
 import com.esotericsoftware.spine.Animation.DrawOrderTimeline;
 import com.esotericsoftware.spine.Animation.EventTimeline;
@@ -133,7 +132,7 @@ public class AnimationState {
 				float nextTime = current.trackLast - next.delay;
 				if (nextTime >= 0) {
 					next.delay = 0;
-					next.trackTime = current.timeScale == 0 ? 0 : (nextTime / current.timeScale + delta) * next.timeScale;
+					next.trackTime += current.timeScale == 0 ? 0 : (nextTime / current.timeScale + delta) * next.timeScale;
 					current.trackTime += currentDelta;
 					setCurrent(i, next, true);
 					while (next.mixingFrom != null) {