Fix failing integration tests (#442)

pom.xml

@@ -72,7 +72,7 @@ under the License.
   </distributionManagement>
 
   <properties>
-    <mavenVersion>4.0.0-rc-4</mavenVersion>
+    <mavenVersion>4.0.0-rc-5</mavenVersion>
     <javaVersion>17</javaVersion>
 
     <guiceVersion>7.0.0</guiceVersion>

src/main/java/org/apache/maven/plugins/resources/ResourcesMojo.java

@@ -429,13 +429,21 @@ protected void executeUserFilterComponents(MavenResourcesExecution mavenResource
      * @return The combined filters.
      */
     protected List<String> getCombinedFiltersList() {
+        // If buildFilters was not injected (can happen with some Maven versions due to field
+        // injection issues in class hierarchies), fall back to reading directly from the project model.
+        List<String> effectiveBuildFilters = buildFilters;
+        if (effectiveBuildFilters == null && project != null) {
+            List<String> projectFilters = project.getBuild().getFilters();
+            effectiveBuildFilters = projectFilters.isEmpty() ? null : projectFilters;
+        }
+
         if (filters == null || filters.isEmpty()) {
-            return useBuildFilters ? buildFilters : null;
+            return useBuildFilters ? effectiveBuildFilters : null;
         } else {
             List<String> result = new ArrayList<>();
 
-            if (useBuildFilters && buildFilters != null) {
-                result.addAll(buildFilters);
+            if (useBuildFilters && effectiveBuildFilters != null) {
+                result.addAll(effectiveBuildFilters);
             }
 
             result.addAll(filters);

src/main/java/org/apache/maven/plugins/resources/TestResourcesMojo.java

@@ -20,6 +20,7 @@
 
 import java.nio.file.Path;
 import java.util.List;
+import java.util.Map;
 
 import org.apache.maven.api.Language;
 import org.apache.maven.api.ProjectScope;
@@ -50,19 +51,11 @@ public class TestResourcesMojo extends ResourcesMojo {
     @Parameter
     private List<Resource> resources;
 
-    /**
-     * Set this to 'true' to bypass copying of test resources.
-     * Its use is NOT RECOMMENDED, but quite convenient on occasion.
-     * @since 2.6
-     */
-    @Parameter(property = "maven.test.skip", defaultValue = "false")
-    private boolean skip;
-
     /**
      * {@inheritDoc}
      */
     public void execute() throws MojoException {
-        if (skip) {
+        if (isTestSkip()) {
             getLog().info("Not copying test resources");
             return;
         }
@@ -75,6 +68,24 @@ public void execute() throws MojoException {
         super.doExecute();
     }
 
+    /**
+     * Returns {@code true} if test resource copying should be skipped.
+     * Checks both the inherited {@code skip} parameter (bound to {@code maven.resources.skip})
+     * and the {@code maven.test.skip} property from the session.
+     *
+     * @return {@code true} if test resources should not be copied
+     * @since 3.x
+     */
+    protected boolean isTestSkip() {
+        if (isSkip()) {
+            return true;
+        }
+        Map<String, String> userProps = session.getUserProperties();
+        Map<String, String> sysProps = session.getSystemProperties();
+        String testSkip = userProps.getOrDefault("maven.test.skip", sysProps.get("maven.test.skip"));
+        return Boolean.parseBoolean(testSkip);
+    }
+
     /** {@inheritDoc} */
     public Path getOutputDirectory() {
         return outputDirectory;