Fix GH-11384: Resolve property before model reflection to avoid recursion

impl/maven-impl/src/main/java/org/apache/maven/impl/model/DefaultModelInterpolator.java

@@ -179,22 +179,24 @@ String doCallback(
             return new MavenBuildTimestamp(request.getSession().getStartTime(), model.getProperties())
                     .formattedTimestamp();
         }
-        // prefixed model reflection
-        for (String prefix : getProjectPrefixes(request)) {
-            if (expression.startsWith(prefix)) {
-                String subExpr = expression.substring(prefix.length());
-                String v = projectProperty(model, projectDir, subExpr, true);
-                if (v != null) {
-                    return v;
-                }
-            }
-        }
         // user properties
         String value = request.getUserProperties().get(expression);
-        // model properties
+        // model properties (check before prefixed model reflection to avoid recursion)
         if (value == null) {
             value = model.getProperties().get(expression);
         }
+        // prefixed model reflection
+        if (value == null) {
+            for (String prefix : getProjectPrefixes(request)) {
+                if (expression.startsWith(prefix)) {
+                    String subExpr = expression.substring(prefix.length());
+                    value = projectProperty(model, projectDir, subExpr, true);
+                    if (value != null) {
+                        return value;
+                    }
+                }
+            }
+        }
         // system properties
         if (value == null) {
             value = request.getSystemProperties().get(expression);

impl/maven-impl/src/test/java/org/apache/maven/impl/model/DefaultModelInterpolatorTest.java

@@ -575,6 +575,26 @@ void shouldIgnorePropertiesWithPomPrefix() throws Exception {
         assertEquals(uninterpolatedName, out.getName());
     }
 
+    @Test
+    void testProjectUrlPropertyDoesNotCauseRecursion() throws Exception {
+        // GH-11384: ${project.url} should resolve to the property "project.url" before
+        // trying to resolve via model reflection, which would cause recursion
+        Map<String, String> modelProperties = new HashMap<>();
+        modelProperties.put("project.url", "https://github.com/slackapi/java-slack-sdk");
+
+        Model model = Model.newBuilder()
+                .url("${project.url}")
+                .properties(modelProperties)
+                .build();
+
+        SimpleProblemCollector collector = new SimpleProblemCollector();
+        Model out = interpolator.interpolateModel(
+                model, null, createModelBuildingRequest(context).build(), collector);
+
+        assertProblemFree(collector);
+        assertEquals("https://github.com/slackapi/java-slack-sdk", out.getUrl());
+    }
+
     @Provides
     @Priority(10)
     @SuppressWarnings("unused")

its/core-it-suite/src/test/java/org/apache/maven/it/MavenITgh11384RecursiveVariableReferenceTest.java

@@ -0,0 +1,52 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.it;
+
+import java.nio.file.Path;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * This is a test set for <a href="https://github.com/apache/maven/issues/11384">GH-11384</a>.
+ *
+ * Verifies that ${project.url} can refer to a property named "project.url" without causing
+ * a recursive variable reference error. This pattern is used by slack-sdk-parent.
+ *
+ * @since 4.0.0-rc-4
+ */
+class MavenITgh11384RecursiveVariableReferenceTest extends AbstractMavenIntegrationTestCase {
+
+    /**
+     * Verify that ${project.url} in the url field can reference a property named project.url
+     * without causing a recursive variable reference error.
+     */
+    @Test
+    void testIt() throws Exception {
+        Path basedir = extractResources("/gh-11384").getAbsoluteFile().toPath();
+
+        Verifier verifier = newVerifier(basedir.toString());
+        verifier.addCliArgument("help:effective-pom");
+        verifier.execute();
+        verifier.verifyErrorFreeLog();
+
+        // Verify that the URL was correctly interpolated from the property
+        verifier.verifyTextInLog("<url>https://github.com/slackapi/java-slack-sdk</url>");
+    }
+}
+

its/core-it-suite/src/test/resources/gh-11384/pom.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.1.0" root="true">
+  <groupId>org.apache.maven.its.mng11384</groupId>
+  <artifactId>test</artifactId>
+  <version>1.0</version>
+  <packaging>pom</packaging>
+
+  <name>Maven Integration Test :: GH-11384</name>
+  <description>Test that project.url can refer to a property named project.url without causing recursion</description>
+
+  <!-- This pattern is used by slack-sdk-parent and should not cause a recursive variable reference error -->
+  <url>${project.url}</url>
+
+  <properties>
+    <project.url>https://github.com/slackapi/java-slack-sdk</project.url>
+  </properties>
+</project>
+