From 1a3e5d18a2b2d9318e50191c00375395df2c14a6 Mon Sep 17 00:00:00 2001
From: Dean Chen <862469039@qq.com>
Date: Wed, 12 Aug 2026 20:03:58 +0500
Subject: [PATCH] compose/loader: keep TCP+UDP when merging same published port

Port merge keyed only on Published, so 443/tcp and 443/udp collapsed
when combining compose files (e.g. stack config with an env-only
override). Include protocol in the merge key.

Fixes #6223

Signed-off-by: Dean Chen <862469039@qq.com>
---
 cli/compose/loader/merge.go      | 19 +++++++++++++++++--
 cli/compose/loader/merge_test.go | 24 ++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/cli/compose/loader/merge.go b/cli/compose/loader/merge.go
index 9d8da3c6d81b..ae0b2eb3b782 100644
--- a/cli/compose/loader/merge.go
+++ b/cli/compose/loader/merge.go
@@ -130,11 +130,21 @@ func toServicePortConfigsMap(s any) (map[any]any, error) {
 	}
 	m := map[any]any{}
 	for _, p := range ports {
-		m[p.Published] = p
+		// Key by published port + protocol so TCP and UDP on the same host
+		// port (e.g. 443/tcp and 443/udp) do not collapse when merging files.
+		m[servicePortMergeKey(p)] = p
 	}
 	return m, nil
 }
 
+func servicePortMergeKey(p types.ServicePortConfig) string {
+	proto := p.Protocol
+	if proto == "" {
+		proto = "tcp"
+	}
+	return fmt.Sprintf("%d/%s", p.Published, proto)
+}
+
 func toServiceVolumeConfigsMap(s any) (map[any]any, error) {
 	volumes, ok := s.([]types.ServiceVolumeConfig)
 	if !ok {
@@ -172,7 +182,12 @@ func toServicePortConfigsSlice(dst reflect.Value, m map[any]any) error {
 	for _, v := range m {
 		s = append(s, v.(types.ServicePortConfig))
 	}
-	sort.Slice(s, func(i, j int) bool { return s[i].Published < s[j].Published })
+	sort.Slice(s, func(i, j int) bool {
+		if s[i].Published != s[j].Published {
+			return s[i].Published < s[j].Published
+		}
+		return s[i].Protocol < s[j].Protocol
+	})
 	dst.Set(reflect.ValueOf(s))
 	return nil
 }
diff --git a/cli/compose/loader/merge_test.go b/cli/compose/loader/merge_test.go
index 11c1e888ead2..c584d1b172bd 100644
--- a/cli/compose/loader/merge_test.go
+++ b/cli/compose/loader/merge_test.go
@@ -301,6 +301,30 @@ func TestLoadMultipleServicePorts(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "same_published_tcp_and_udp",
+			portBase: map[string]any{
+				"ports": []any{
+					"443:443",
+					"443:443/udp",
+				},
+			},
+			portOverride: map[string]any{},
+			expected: []types.ServicePortConfig{
+				{
+					Mode:      "ingress",
+					Published: 443,
+					Target:    443,
+					Protocol:  "tcp",
+				},
+				{
+					Mode:      "ingress",
+					Published: 443,
+					Target:    443,
+					Protocol:  "udp",
+				},
+			},
+		},
 	}
 
 	for _, tc := range portsCases {