try harder for to avoid scheduling dupes removal when adding changes: important use case is loading of the data from disk, it might be already sorted

platform/lang-impl/src/com/intellij/util/indexing/containers/ChangeBufferingList.java

@@ -73,9 +73,12 @@ public class ChangeBufferingList implements Cloneable {
   }
 
   private void addChange(int value) {
+    if (value < 0) {
+      if (!hasRemovals) hasRemovals = true;
+    } else if (!mayHaveDupes && length > 0 && changes[length - 1] >= value) {
+      mayHaveDupes = true;
+    }
     changes[length++] = value;
-    if (value < 0 && !hasRemovals) hasRemovals = true;
-    if(!mayHaveDupes) mayHaveDupes = true;
   }
 
   public void remove(int value) {