From 7d015ba28edcf835256422d384988b059ed4bc5c Mon Sep 17 00:00:00 2001
From: Karl Gaissmaier <karl.gaissmaier@uni-ulm.de>
Date: Sat, 30 Jul 2022 19:06:00 +0200
Subject: [PATCH] bump required version

---
 go.mod     |  2 +-
 go.sum     |  2 ++
 iprange.go | 17 ++++++++++-------
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/go.mod b/go.mod
index 4b33d94..4e9c9b6 100644
--- a/go.mod
+++ b/go.mod
@@ -2,4 +2,4 @@ module github.com/gaissmai/iprange
 
 go 1.18
 
-require github.com/gaissmai/extnetip v0.2.0
+require github.com/gaissmai/extnetip v0.3.0
diff --git a/go.sum b/go.sum
index 2361c8e..87174a7 100644
--- a/go.sum
+++ b/go.sum
@@ -1,2 +1,4 @@
 github.com/gaissmai/extnetip v0.2.0 h1:m9BAcG3RbEyGsWmC6RCBgH7HOttPgeIMZFZsJoqt+30=
 github.com/gaissmai/extnetip v0.2.0/go.mod h1:M3NWlyFKaVosQXWXKKeIPK+5VM4U85DahdIqNYX4TK4=
+github.com/gaissmai/extnetip v0.3.0 h1:JNCEMbKAb9tE3SthpAmikPVuR2ifyQt5IKt30RyCSxE=
+github.com/gaissmai/extnetip v0.3.0/go.mod h1:M3NWlyFKaVosQXWXKKeIPK+5VM4U85DahdIqNYX4TK4=
diff --git a/iprange.go b/iprange.go
index 22d69d8..2a818f0 100644
--- a/iprange.go
+++ b/iprange.go
@@ -151,7 +151,7 @@ func (r IPRange) Prefixes() []netip.Prefix {
 //
 // It appends to dst the netip.Prefix entries that covers r.
 func (r IPRange) PrefixesAppend(dst []netip.Prefix) []netip.Prefix {
-	return extnetip.AppendPrefixes(dst, r.first, r.last)
+	return extnetip.PrefixesAppend(dst, r.first, r.last)
 }
 
 // String returns the string form of the IPRange.
@@ -208,12 +208,15 @@ func Merge(in []IPRange) (out []IPRange) {
 		case topic.isDisjunctLeft(r):
 			// disjoint [f...l]  [f...l]
 			out = append(out, r)
+		case topic.covers(r):
+			// no-op
+			continue
 		case topic.last.Less(r.last):
 			// partial overlap [f......l]
-			//                       [f....l]
+			//                      [f....l]
 			topic.last = r.last
 		default:
-			// no-op: covers or equal
+			panic("unreachable")
 		}
 	}
 
@@ -254,18 +257,18 @@ func (r IPRange) Remove(in []IPRange) (out []IPRange) {
 			// left overlap, move cursor
 			r.first = m.last.Next()
 		case m.first.Compare(r.first) > 0:
-			// right overlap, save [r.first, d.first-1)
+			// right overlap, save [r.first, m.first-1)
 			out = append(out, IPRange{r.first, m.first.Prev()})
-			// new r, (d.last, r.last]
+			// new r first
 			r.first = m.last.Next()
 		default:
 			panic("unreachable")
 		}
-		// overflow from d.last.Next()
+		// test for overflow from last.Next()
 		if !r.first.IsValid() {
 			return out
 		}
-		// cursor moved behind r.last
+		// test if cursor moved behind r.last
 		if r.last.Less(r.first) {
 			return out
 		}