From bbc4a35617db04508eaf6d8accf5d95825015ade Mon Sep 17 00:00:00 2001
From: Yiding Cui <winoros@gmail.com>
Date: Wed, 12 May 2021 18:20:55 +0800
Subject: [PATCH] ranger: fix the case which could have duplicate ranges

---
 util/ranger/ranger.go      |  6 +++---
 util/ranger/ranger_test.go | 10 +++++++++-
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/util/ranger/ranger.go b/util/ranger/ranger.go
index 4f1efef7a7d90..d69c3dbc02392 100644
--- a/util/ranger/ranger.go
+++ b/util/ranger/ranger.go
@@ -474,7 +474,7 @@ func fixPrefixColRange(ranges []*Range, lengths []int, tp []*types.FieldType) bo
 	for _, ran := range ranges {
 		lowTail := len(ran.LowVal) - 1
 		for i := 0; i < lowTail; i++ {
-			CutDatumByPrefixLen(&ran.LowVal[i], lengths[i], tp[i])
+			hasCut = CutDatumByPrefixLen(&ran.LowVal[i], lengths[i], tp[i]) || hasCut
 		}
 		lowCut := CutDatumByPrefixLen(&ran.LowVal[lowTail], lengths[lowTail], tp[lowTail])
 		// If the length of the last column of LowVal is equal to the prefix length, LowExclude should be set false.
@@ -485,13 +485,13 @@ func fixPrefixColRange(ranges []*Range, lengths []int, tp []*types.FieldType) bo
 		}
 		highTail := len(ran.HighVal) - 1
 		for i := 0; i < highTail; i++ {
-			CutDatumByPrefixLen(&ran.HighVal[i], lengths[i], tp[i])
+			hasCut = CutDatumByPrefixLen(&ran.HighVal[i], lengths[i], tp[i]) || hasCut
 		}
 		highCut := CutDatumByPrefixLen(&ran.HighVal[highTail], lengths[highTail], tp[highTail])
 		if highCut {
 			ran.HighExclude = false
 		}
-		hasCut = lowCut || highCut
+		hasCut = hasCut || lowCut || highCut
 	}
 	return hasCut
 }
diff --git a/util/ranger/ranger_test.go b/util/ranger/ranger_test.go
index 194ba1e779dc3..9b781e968731a 100644
--- a/util/ranger/ranger_test.go
+++ b/util/ranger/ranger_test.go
@@ -351,7 +351,8 @@ create table t(
 	index idx_cb(c, a),
 	index idx_d(d(2)),
 	index idx_e(e(2)),
-	index idx_f(f)
+	index idx_f(f),
+	index idx_de(d(2), e)
 )`)
 
 	tests := []struct {
@@ -620,6 +621,13 @@ create table t(
 			filterConds: "[like(test.t.f, @%, 92)]",
 			resultStr:   "[[NULL,+inf]]",
 		},
+		{
+			indexPos:    5,
+			exprStr:     "d in ('aab', 'aac') and e = 'a'",
+			accessConds: "[in(test.t.d, aab, aac) eq(test.t.e, a)]",
+			filterConds: "[in(test.t.d, aab, aac)]",
+			resultStr:   "[[\"aa\" 0x61,\"aa\" 0x61]]",
+		},
 	}
 
 	collate.SetNewCollationEnabledForTest(true)