Revert "updated the logic for reducing buckets"

This reverts commit 34386f9.

Author: vinaykpud

server/src/main/java/org/opensearch/search/aggregations/bucket/terms/InternalTerms.java

@@ -466,33 +466,45 @@ For backward compatibility, we disable the merge sort and use ({@link InternalTe
             final Comparator<MultiBucketsAggregation.Bucket> cmp = order.comparator();
             if (size < reducedBuckets.size()) {
                 ArrayUtil.select(reducedBucketsArr, 0, reducedBuckets.size(), size, cmp);
-            }
-            int selectedSize = 0;
-            for (B bucket : reducedBucketsArr) {
-                if (sumDocCountError == -1) {
-                    bucket.setDocCountError(-1);
-                } else {
-                    final long finalSumDocCountError = sumDocCountError;
-                    bucket.setDocCountError(docCountError -> docCountError + finalSumDocCountError);
-                }
-                if (bucket.getDocCount() >= localBucketCountThresholds.getMinDocCount()) {
-                    B removed = ((selectedSize == size) ? bucket : null);
-                    if (removed != null) {
-                        otherDocCount += removed.getDocCount();
-                        reduceContext.consumeBucketsAndMaybeBreak(-countInnerBucket(removed));
+                int selectedSize = 0;
+                for (B bucket : reducedBucketsArr) {
+                    if (sumDocCountError == -1) {
+                        bucket.setDocCountError(-1);
                     } else {
-                        selectedSize++;
-                        reduceContext.consumeBucketsAndMaybeBreak(1);
+                        final long finalSumDocCountError = sumDocCountError;
+                        bucket.setDocCountError(docCountError -> docCountError + finalSumDocCountError);
+                    }
+                    if (bucket.getDocCount() >= localBucketCountThresholds.getMinDocCount()) {
+                        B removed = ((selectedSize == size) ? bucket : null);
+                        if (removed != null) {
+                            otherDocCount += removed.getDocCount();
+                            reduceContext.consumeBucketsAndMaybeBreak(-countInnerBucket(removed));
+                        } else {
+                            selectedSize++;
+                            reduceContext.consumeBucketsAndMaybeBreak(1);
+                        }
+                    } else {
+                        reduceContext.consumeBucketsAndMaybeBreak(-countInnerBucket(bucket));
                     }
-                } else {
-                    reduceContext.consumeBucketsAndMaybeBreak(-countInnerBucket(bucket));
                 }
-            }
-            if (selectedSize != size) {
                 list = createBucketsArray(selectedSize);
                 System.arraycopy(reducedBucketsArr, 0, list, 0, selectedSize);
             } else {
+                // since only else case possible is size == reducedBuckets.size() we can use the entire list of reduced buckets
                 list = reducedBucketsArr;
+                for (B bucket : reducedBucketsArr) {
+                    if (sumDocCountError == -1) {
+                        bucket.setDocCountError(-1);
+                    } else {
+                        final long finalSumDocCountError = sumDocCountError;
+                        bucket.setDocCountError(docCountError -> docCountError + finalSumDocCountError);
+                    }
+                    if (bucket.getDocCount() >= localBucketCountThresholds.getMinDocCount()) {
+                        reduceContext.consumeBucketsAndMaybeBreak(1);
+                    } else {
+                        reduceContext.consumeBucketsAndMaybeBreak(-countInnerBucket(bucket));
+                    }
+                }
             }
             Arrays.sort(list, cmp);
         } else {