From 8a4260275accc0e7660c36c16662c960c3e07155 Mon Sep 17 00:00:00 2001
From: Travis Bischel <twmb@protonmail.com>
Date: Fri, 19 Feb 2021 18:49:23 -0700
Subject: [PATCH] kversion: fix overflow panic for SetMaxKeyVersion

---
 pkg/kversion/kversion.go      |  2 +-
 pkg/kversion/kversion_test.go | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/pkg/kversion/kversion.go b/pkg/kversion/kversion.go
index 3b629367..10b09eca 100644
--- a/pkg/kversion/kversion.go
+++ b/pkg/kversion/kversion.go
@@ -76,7 +76,7 @@ func (vs *Versions) SetMaxKeyVersion(k, v int16) {
 	if k < 0 || v < 0 && int(k) >= len(vs.k2v)+1 {
 		return
 	}
-	needLen := int(k + 1)
+	needLen := int(k) + 1
 	for len(vs.k2v) < needLen {
 		vs.k2v = append(vs.k2v, -1)
 	}
diff --git a/pkg/kversion/kversion_test.go b/pkg/kversion/kversion_test.go
index c3bae180..f443bf26 100644
--- a/pkg/kversion/kversion_test.go
+++ b/pkg/kversion/kversion_test.go
@@ -1,9 +1,22 @@
 package kversion
 
 import (
+	"math"
 	"testing"
 )
 
+func TestSetMaxKeyVersion(t *testing.T) {
+	var vs Versions
+	for i := int16(0); i < math.MaxInt16; i++ {
+		vs.SetMaxKeyVersion(i, i)
+	}
+	for i, v := range vs.k2v {
+		if int16(i) != v {
+			t.Errorf("set incorrect: at %d got %d != exp %d", i, v, i)
+		}
+	}
+}
+
 func TestVersionGuess(t *testing.T) {
 	// Cases where last can be empty.
 	{