From 41e882f80ba812f4b7904bc7b5fc6c745d6077c8 Mon Sep 17 00:00:00 2001
From: Taewoo Kim <taew.kim@mail.utoronto.ca>
Date: Thu, 22 Jul 2021 15:07:01 -0400
Subject: [PATCH] Check input value is duplicated when quantile queue is full
 (#7091)

Co-authored-by: Taewoo Kim <taewoo@layer6.com>
---
 src/common/quantile.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/common/quantile.h b/src/common/quantile.h
index 4167adbe8..bdfe387c7 100644
--- a/src/common/quantile.h
+++ b/src/common/quantile.h
@@ -575,7 +575,7 @@ class QuantileSketchTemplate {
    */
   inline void Push(DType x, RType w = 1) {
     if (w == static_cast<RType>(0)) return;
-    if (inqueue.qtail == inqueue.queue.size()) {
+    if (inqueue.qtail == inqueue.queue.size() && inqueue.queue[inqueue.qtail - 1].value != x) {
       // jump from lazy one value to limit_size * 2
       if (inqueue.queue.size() == 1) {
         inqueue.queue.resize(limit_size * 2);