fix incorrect ignored dependencies in verbose analyze output

src/it/projects/mdep-1645-verbose-no-duplicate-ignored/invoker.properties

@@ -0,0 +1,18 @@
+# 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.
+
+invoker.goals = clean ${project.groupId}:${project.artifactId}:${project.version}:analyze

src/it/projects/mdep-1645-verbose-no-duplicate-ignored/pom.xml

@@ -0,0 +1,61 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+  ~ 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.
+  -->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>org.apache.maven.its.dependency</groupId>
+  <artifactId>mdep-1645</artifactId>
+  <version>1.0-SNAPSHOT</version>
+
+  <name>Test</name>
+  <description>
+    Test dependency:analyze -Dverbose does not duplicate entries in ignored section
+  </description>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.apache.commons</groupId>
+      <artifactId>commons-text</artifactId>
+      <version>1.10.0</version>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <pluginManagement>
+      <plugins>
+        <plugin>
+          <artifactId>maven-dependency-plugin</artifactId>
+          <version>@project.version@</version>
+          <configuration>
+            <verbose>true</verbose>
+          </configuration>
+        </plugin>
+      </plugins>
+    </pluginManagement>
+  </build>
+</project>

src/it/projects/mdep-1645-verbose-no-duplicate-ignored/src/main/java/test/App.java

@@ -0,0 +1,25 @@
+/*
+ * 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 test;
+import org.apache.commons.lang3.StringUtils;
+public class App {
+    public void test() {
+        System.out.println(StringUtils.capitalize("hello"));
+    }
+}

src/it/projects/mdep-1645-verbose-no-duplicate-ignored/verify.groovy

@@ -0,0 +1,36 @@
+/*
+ * 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.
+ */
+
+File buildLog = new File( basedir, "build.log" )
+assert buildLog.exists()
+
+String log = buildLog.getText( "UTF-8" )
+
+// warning sections should be present
+assert log.contains( '[WARNING] Used undeclared dependencies found:' )
+assert log.contains( '[WARNING]    org.apache.commons:commons-lang3:jar:3.12.0:compile' )
+assert log.contains( '[WARNING]       class org.apache.commons.lang3.StringUtils' )
+assert log.contains( '[WARNING] Unused declared dependencies found:' )
+assert log.contains( '[WARNING]    org.apache.commons:commons-text:jar:1.10.0:compile' )
+
+// when no ignoredDependencies are configured, the ignored sections should not appear
+assert !log.contains( 'Ignored used undeclared dependencies' )
+assert !log.contains( 'Ignored unused declared dependencies' )
+
+return true

src/main/java/org/apache/maven/plugins/dependency/analyze/AbstractAnalyzeMojo.java

@@ -21,6 +21,7 @@
 import java.io.File;
 import java.io.StringWriter;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
@@ -558,9 +559,18 @@ private void writeScriptableOutput(Set<Artifact> artifacts) {
         }
     }
 
+    /**
+     * Removes artifacts matching any of the given exclude patterns from the source set
+     * and returns the removed artifacts. When {@code excludes} is null or empty, no
+     * artifacts are removed and an empty set is returned.
+     *
+     * @param artifacts the source set of artifacts (mutated in place)
+     * @param excludes  exclude patterns, may be null or empty
+     * @return the artifacts that were removed from the source set
+     */
     private Set<Artifact> filterDependencies(Set<Artifact> artifacts, String[] excludes) {
         if (excludes == null || excludes.length == 0) {
-            return artifacts;
+            return Collections.emptySet();
         }
         ArtifactFilter filter = new StrictPatternExcludesArtifactFilter(Arrays.asList(excludes));
         Set<Artifact> result = new LinkedHashSet<>();