From b06e75eb45a5090abaf51a370ea05008885c6353 Mon Sep 17 00:00:00 2001
From: Remy Suen <remy.suen@docker.com>
Date: Wed, 23 Jul 2025 13:39:52 -0400
Subject: [PATCH] Improve handling of malformed image attribute values in
 Compose

Signed-off-by: Remy Suen <remy.suen@docker.com>
---
 CHANGELOG.md                          |  8 +++
 internal/compose/documentLink.go      | 40 ++++++-----
 internal/compose/documentLink_test.go | 98 ++++++++++++++++++++++++++-
 3 files changed, 129 insertions(+), 17 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 37c2d28..442d5fc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,14 @@
 
 All notable changes to the Docker Language Server will be documented in this file.
 
+## [Unreleased]
+
+### Fixed
+
+- Compose
+  - textDocument/documentLink
+    - improve handling of malformed image attribute values with registry prefixes ([#369](https://github.com/docker/docker-language-server/issues/369))
+
 ## [0.14.0] - 2025-07-16
 
 ### Added
diff --git a/internal/compose/documentLink.go b/internal/compose/documentLink.go
index 0bb479c..f18039f 100644
--- a/internal/compose/documentLink.go
+++ b/internal/compose/documentLink.go
@@ -282,16 +282,24 @@ func DocumentLink(ctx context.Context, documentURI protocol.URI, doc document.Co
 	return links, nil
 }
 
+func extractNonDockerHubImageLink(nodeValue, prefix, uriPrefix string, startIndex uint) (string, string) {
+	if len(nodeValue) <= len(prefix)+1 {
+		return "", ""
+	}
+	idx := strings.LastIndex(nodeValue, ":")
+	lastSlashIdx := strings.LastIndex(nodeValue, "/")
+	if (idx != -1 && lastSlashIdx > idx) || strings.Index(nodeValue, "/") == lastSlashIdx {
+		return "", ""
+	}
+	if idx == -1 {
+		return nodeValue, fmt.Sprintf("%v%v", uriPrefix, nodeValue[startIndex:])
+	}
+	return nodeValue[0:idx], fmt.Sprintf("%v%v", uriPrefix, nodeValue[startIndex:idx])
+}
+
 func extractImageLink(nodeValue string) (string, string) {
 	if strings.HasPrefix(nodeValue, "ghcr.io") {
-		if len(nodeValue) <= 8 {
-			return "", ""
-		}
-		idx := strings.LastIndex(nodeValue, ":")
-		if idx == -1 {
-			return nodeValue, fmt.Sprintf("https://%v", nodeValue)
-		}
-		return nodeValue[0:idx], fmt.Sprintf("https://%v", nodeValue[0:idx])
+		return extractNonDockerHubImageLink(nodeValue, "ghcr.io", "https://", 0)
 	}
 
 	if strings.HasPrefix(nodeValue, "mcr.microsoft.com") {
@@ -299,6 +307,13 @@ func extractImageLink(nodeValue string) (string, string) {
 			return "", ""
 		}
 		idx := strings.LastIndex(nodeValue, ":")
+		if idx == 17 {
+			return "", ""
+		}
+		lastSlashIdx := strings.LastIndex(nodeValue, "/")
+		if lastSlashIdx == idx-1 || (idx != -1 && lastSlashIdx > idx) {
+			return "", ""
+		}
 		if idx == -1 {
 			return nodeValue, fmt.Sprintf("https://mcr.microsoft.com/artifact/mar/%v", nodeValue[18:])
 		}
@@ -306,14 +321,7 @@ func extractImageLink(nodeValue string) (string, string) {
 	}
 
 	if strings.HasPrefix(nodeValue, "quay.io") {
-		if len(nodeValue) <= 8 {
-			return "", ""
-		}
-		idx := strings.LastIndex(nodeValue, ":")
-		if idx == -1 {
-			return nodeValue, fmt.Sprintf("https://quay.io/repository/%v", nodeValue[8:])
-		}
-		return nodeValue[0:idx], fmt.Sprintf("https://quay.io/repository/%v", nodeValue[8:idx])
+		return extractNonDockerHubImageLink(nodeValue, "quay.io", "https://quay.io/repository/", 8)
 	}
 
 	idx := strings.LastIndex(nodeValue, ":")
diff --git a/internal/compose/documentLink_test.go b/internal/compose/documentLink_test.go
index f691046..68629c9 100644
--- a/internal/compose/documentLink_test.go
+++ b/internal/compose/documentLink_test.go
@@ -517,12 +517,44 @@ services:
     image: ghcr.io:`,
 			links: nil,
 		},
+		{
+			name: "image: ghcr.io:tag",
+			content: `
+services:
+  test:
+    image: ghcr.io:tag`,
+			links: []protocol.DocumentLink{},
+		},
+		{
+			name: "image: ghcr.io/:tag",
+			content: `
+services:
+  test:
+    image: ghcr.io/:tag`,
+			links: []protocol.DocumentLink{},
+		},
+		{
+			name: "image: ghcr.io/:tag",
+			content: `
+services:
+  test:
+    image: ghcr.io:tag/`,
+			links: []protocol.DocumentLink{},
+		},
+		{
+			name: "image: ghcr.io/:tag",
+			content: `
+services:
+  test:
+    image: ghcr.io/:tag/`,
+			links: []protocol.DocumentLink{},
+		},
 		{
 			name: "image: \"ghcr.io:\"",
 			content: `
 services:
   test:
-    image: "ghcr.io:"`,
+    image: "ghcr.io:tag"`,
 			links: []protocol.DocumentLink{},
 		},
 		{
@@ -617,6 +649,38 @@ services:
     image: mcr.microsoft.com:`,
 			links: nil,
 		},
+		{
+			name: "image: mcr.microsoft.com:tag",
+			content: `
+services:
+  test:
+    image: mcr.microsoft.com:tag`,
+			links: []protocol.DocumentLink{},
+		},
+		{
+			name: "image: mcr.microsoft.com/:tag",
+			content: `
+services:
+  test:
+    image: mcr.microsoft.com/:tag`,
+			links: []protocol.DocumentLink{},
+		},
+		{
+			name: "image: mcr.microsoft.com:tag/",
+			content: `
+services:
+  test:
+    image: mcr.microsoft.com:tag/`,
+			links: []protocol.DocumentLink{},
+		},
+		{
+			name: "image: mcr.microsoft.com/:tag/",
+			content: `
+services:
+  test:
+    image: mcr.microsoft.com/:tag/`,
+			links: []protocol.DocumentLink{},
+		},
 		{
 			name: "image: \"mcr.microsoft.com:\"",
 			content: `
@@ -683,6 +747,38 @@ services:
     image: quay.io:`,
 			links: nil,
 		},
+		{
+			name: "image: quay.io:tag",
+			content: `
+services:
+  test:
+    image: quay.io:tag`,
+			links: []protocol.DocumentLink{},
+		},
+		{
+			name: "image: quay.io/:tag",
+			content: `
+services:
+  test:
+    image: quay.io/:tag`,
+			links: []protocol.DocumentLink{},
+		},
+		{
+			name: "image: quay.io:tag/",
+			content: `
+services:
+  test:
+    image: quay.io:tag/`,
+			links: []protocol.DocumentLink{},
+		},
+		{
+			name: "image: quay.io/:tag/",
+			content: `
+services:
+  test:
+    image: quay.io/:tag/`,
+			links: []protocol.DocumentLink{},
+		},
 		{
 			name: "image: \"quay.io:\"",
 			content: `