Fix: IPSet mutations (#357)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Loyalsoldier <10487845+Loyalsoldier@users.noreply.github.com>

Author: Copilot

lib/container.go

@@ -89,32 +89,46 @@ func (c *container) Add(entry *Entry, opts ...IgnoreIPOption) error {
 		}
 		switch ignoreIPType {
 		case IPv4:
-			if !val.hasIPv6Builder() {
-				val.ipv6Builder = new(netipx.IPSetBuilder)
+			if ipv6set != nil {
+				if !val.hasIPv6Builder() {
+					val.ipv6Builder = new(netipx.IPSetBuilder)
+				}
+				val.ipv6Builder.AddSet(ipv6set)
+				val.ipv6Set = nil
 			}
-			val.ipv6Builder.AddSet(ipv6set)
 		case IPv6:
-			if !val.hasIPv4Builder() {
-				val.ipv4Builder = new(netipx.IPSetBuilder)
+			if ipv4set != nil {
+				if !val.hasIPv4Builder() {
+					val.ipv4Builder = new(netipx.IPSetBuilder)
+				}
+				val.ipv4Builder.AddSet(ipv4set)
+				val.ipv4Set = nil
 			}
-			val.ipv4Builder.AddSet(ipv4set)
 		default:
-			if !val.hasIPv4Builder() {
-				val.ipv4Builder = new(netipx.IPSetBuilder)
+			if ipv4set != nil {
+				if !val.hasIPv4Builder() {
+					val.ipv4Builder = new(netipx.IPSetBuilder)
+				}
+				val.ipv4Builder.AddSet(ipv4set)
+				val.ipv4Set = nil
 			}
-			if !val.hasIPv6Builder() {
-				val.ipv6Builder = new(netipx.IPSetBuilder)
+			if ipv6set != nil {
+				if !val.hasIPv6Builder() {
+					val.ipv6Builder = new(netipx.IPSetBuilder)
+				}
+				val.ipv6Builder.AddSet(ipv6set)
+				val.ipv6Set = nil
 			}
-			val.ipv4Builder.AddSet(ipv4set)
-			val.ipv6Builder.AddSet(ipv6set)
 		}
 
 	case false:
 		switch ignoreIPType {
 		case IPv4:
 			entry.ipv4Builder = nil
+			entry.ipv4Set = nil
 		case IPv6:
 			entry.ipv6Builder = nil
+			entry.ipv6Set = nil
 		}
 		c.entries[name] = entry
 	}
@@ -155,32 +169,46 @@ func (c *container) Remove(entry *Entry, rCase CaseRemove, opts ...IgnoreIPOptio
 
 		switch ignoreIPType {
 		case IPv4:
-			if !val.hasIPv6Builder() {
-				val.ipv6Builder = new(netipx.IPSetBuilder)
+			if ipv6set != nil {
+				if !val.hasIPv6Builder() {
+					val.ipv6Builder = new(netipx.IPSetBuilder)
+				}
+				val.ipv6Builder.RemoveSet(ipv6set)
+				val.ipv6Set = nil
 			}
-			val.ipv6Builder.RemoveSet(ipv6set)
 		case IPv6:
-			if !val.hasIPv4Builder() {
-				val.ipv4Builder = new(netipx.IPSetBuilder)
+			if ipv4set != nil {
+				if !val.hasIPv4Builder() {
+					val.ipv4Builder = new(netipx.IPSetBuilder)
+				}
+				val.ipv4Builder.RemoveSet(ipv4set)
+				val.ipv4Set = nil
 			}
-			val.ipv4Builder.RemoveSet(ipv4set)
 		default:
-			if !val.hasIPv4Builder() {
-				val.ipv4Builder = new(netipx.IPSetBuilder)
+			if ipv4set != nil {
+				if !val.hasIPv4Builder() {
+					val.ipv4Builder = new(netipx.IPSetBuilder)
+				}
+				val.ipv4Builder.RemoveSet(ipv4set)
+				val.ipv4Set = nil
 			}
-			if !val.hasIPv6Builder() {
-				val.ipv6Builder = new(netipx.IPSetBuilder)
+			if ipv6set != nil {
+				if !val.hasIPv6Builder() {
+					val.ipv6Builder = new(netipx.IPSetBuilder)
+				}
+				val.ipv6Builder.RemoveSet(ipv6set)
+				val.ipv6Set = nil
 			}
-			val.ipv4Builder.RemoveSet(ipv4set)
-			val.ipv6Builder.RemoveSet(ipv6set)
 		}
 
 	case CaseRemoveEntry:
 		switch ignoreIPType {
 		case IPv4:
 			val.ipv6Builder = nil
+			val.ipv6Set = nil
 		case IPv6:
 			val.ipv4Builder = nil
+			val.ipv4Set = nil
 		default:
 			delete(c.entries, name)
 		}

lib/entry.go

@@ -253,11 +253,13 @@ func (e *Entry) add(prefix *netip.Prefix, ipType IPType) error {
 			e.ipv4Builder = new(netipx.IPSetBuilder)
 		}
 		e.ipv4Builder.AddPrefix(*prefix)
+		e.ipv4Set = nil
 	case IPv6:
 		if !e.hasIPv6Builder() {
 			e.ipv6Builder = new(netipx.IPSetBuilder)
 		}
 		e.ipv6Builder.AddPrefix(*prefix)
+		e.ipv6Set = nil
 	default:
 		return ErrInvalidIPType
 	}
@@ -270,10 +272,12 @@ func (e *Entry) remove(prefix *netip.Prefix, ipType IPType) error {
 	case IPv4:
 		if e.hasIPv4Builder() {
 			e.ipv4Builder.RemovePrefix(*prefix)
+			e.ipv4Set = nil
 		}
 	case IPv6:
 		if e.hasIPv6Builder() {
 			e.ipv6Builder.RemovePrefix(*prefix)
+			e.ipv6Set = nil
 		}
 	default:
 		return ErrInvalidIPType