From ad5e085ebe72d5799122d7da575fd1fce36a6965 Mon Sep 17 00:00:00 2001
From: Tamas Cservenak <tamas@cservenak.net>
Date: Mon, 18 Dec 2023 16:31:24 +0100
Subject: [PATCH] [MNG-7959] User controlled rewrite (#1351)

Extra handling if redirection happens within same GAV.

---

https://issues.apache.org/jira/browse/MNG-7959
---
 .../internal/ArtifactDescriptorUtils.java     | 11 ++++++++++
 .../DefaultArtifactDescriptorReader.java      | 22 ++++++++++++++-----
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/maven-resolver-provider/src/main/java/org/apache/maven/repository/internal/ArtifactDescriptorUtils.java b/maven-resolver-provider/src/main/java/org/apache/maven/repository/internal/ArtifactDescriptorUtils.java
index 244bd6b984ef..d01265f43d1e 100644
--- a/maven-resolver-provider/src/main/java/org/apache/maven/repository/internal/ArtifactDescriptorUtils.java
+++ b/maven-resolver-provider/src/main/java/org/apache/maven/repository/internal/ArtifactDescriptorUtils.java
@@ -43,6 +43,17 @@ public static Artifact toPomArtifact(Artifact artifact) {
         return pomArtifact;
     }
 
+    /**
+     * Creates POM artifact out of passed in artifact by dropping classifier (if exists) and rewriting extension to
+     * "pom". Unconditionally, unlike {@link #toPomArtifact(Artifact)} that does this only for artifacts without
+     * classifiers.
+     *
+     * @since 4.0.0
+     */
+    public static Artifact toPomArtifactUnconditionally(Artifact artifact) {
+        return new DefaultArtifact(artifact.getGroupId(), artifact.getArtifactId(), "pom", artifact.getVersion());
+    }
+
     public static RemoteRepository toRemoteRepository(Repository repository) {
         RemoteRepository.Builder builder =
                 new RemoteRepository.Builder(repository.getId(), repository.getLayout(), repository.getUrl());
diff --git a/maven-resolver-provider/src/main/java/org/apache/maven/repository/internal/DefaultArtifactDescriptorReader.java b/maven-resolver-provider/src/main/java/org/apache/maven/repository/internal/DefaultArtifactDescriptorReader.java
index 31660e279928..a8c61693fa64 100644
--- a/maven-resolver-provider/src/main/java/org/apache/maven/repository/internal/DefaultArtifactDescriptorReader.java
+++ b/maven-resolver-provider/src/main/java/org/apache/maven/repository/internal/DefaultArtifactDescriptorReader.java
@@ -26,7 +26,6 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Properties;
-import java.util.Set;
 
 import org.apache.maven.model.Model;
 import org.apache.maven.model.building.ArtifactModelSource;
@@ -129,9 +128,9 @@ private Model loadPom(
             throws ArtifactDescriptorException {
         RequestTrace trace = RequestTrace.newChild(request.getTrace(), request);
 
-        Set<String> visited = new LinkedHashSet<>();
+        LinkedHashSet<String> visited = new LinkedHashSet<>();
         for (Artifact a = request.getArtifact(); ; ) {
-            Artifact pomArtifact = ArtifactDescriptorUtils.toPomArtifact(a);
+            Artifact pomArtifact = ArtifactDescriptorUtils.toPomArtifactUnconditionally(a);
             try {
                 VersionRequest versionRequest =
                         new VersionRequest(a, request.getRepositories(), request.getRequestContext());
@@ -239,15 +238,26 @@ private Model loadPom(
 
             Artifact relocatedArtifact = getRelocation(session, result, model);
             if (relocatedArtifact != null) {
-                result.addRelocation(a);
-                a = relocatedArtifact;
-                result.setArtifact(a);
+                if (withinSameGav(relocatedArtifact, a)) {
+                    result.setArtifact(relocatedArtifact);
+                    return model; // they share same model
+                } else {
+                    result.addRelocation(a);
+                    a = relocatedArtifact;
+                    result.setArtifact(a);
+                }
             } else {
                 return model;
             }
         }
     }
 
+    private boolean withinSameGav(Artifact a1, Artifact a2) {
+        return Objects.equals(a1.getGroupId(), a2.getGroupId())
+                && Objects.equals(a1.getArtifactId(), a2.getArtifactId())
+                && Objects.equals(a1.getVersion(), a2.getVersion());
+    }
+
     private Properties toProperties(Map<String, String> dominant, Map<String, String> recessive) {
         Properties props = new Properties();
         if (recessive != null) {