[MNG-6229] Write out optionality in Core IT Plugins for collection and resolution

Write out " (optional)" in the log entry as well as to the file for later
analysis.
diff --git a/core-it-suite/src/test/java/org/apache/maven/it/MavenITmng0947OptionalDependencyTest.java b/core-it-suite/src/test/java/org/apache/maven/it/MavenITmng0947OptionalDependencyTest.java
index 78c48e8..b0ca8f2 100644
--- a/core-it-suite/src/test/java/org/apache/maven/it/MavenITmng0947OptionalDependencyTest.java
+++ b/core-it-suite/src/test/java/org/apache/maven/it/MavenITmng0947OptionalDependencyTest.java
@@ -27,7 +27,7 @@
 
 /**
  * This is a test set for <a href="https://issues.apache.org/jira/browse/MNG-947">MNG-947</a>.
- * 
+ *
  * @author Benjamin Bentmann
  */
 public class MavenITmng0947OptionalDependencyTest
@@ -60,20 +60,20 @@
         verifier.resetStreams();
 
         List<String> compile = verifier.loadLines( "target/compile.txt", "UTF-8" );
-        assertTrue( compile.toString(), compile.contains( "org.apache.maven.its.mng0947:d:jar:0.1" ) );
-        assertTrue( compile.toString(), compile.contains( "org.apache.maven.its.mng0947:e:jar:0.1" ) );
+        assertTrue( compile.toString(), compile.contains( "org.apache.maven.its.mng0947:d:jar:0.1 (optional)" ) );
+        assertTrue( compile.toString(), compile.contains( "org.apache.maven.its.mng0947:e:jar:0.1 (optional)" ) );
         assertEquals( 2, compile.size() );
 
         List<String> runtime = verifier.loadLines( "target/runtime.txt", "UTF-8" );
         assertTrue( runtime.toString(), runtime.contains( "org.apache.maven.its.mng0947:c:jar:0.1" ) );
-        assertTrue( runtime.toString(), runtime.contains( "org.apache.maven.its.mng0947:d:jar:0.1" ) );
-        assertTrue( runtime.toString(), runtime.contains( "org.apache.maven.its.mng0947:e:jar:0.1" ) );
+        assertTrue( runtime.toString(), runtime.contains( "org.apache.maven.its.mng0947:d:jar:0.1 (optional)" ) );
+        assertTrue( runtime.toString(), runtime.contains( "org.apache.maven.its.mng0947:e:jar:0.1 (optional)" ) );
         assertEquals( 3, runtime.size() );
 
         List<String> test = verifier.loadLines( "target/test.txt", "UTF-8" );
         assertTrue( test.toString(), test.contains( "org.apache.maven.its.mng0947:c:jar:0.1" ) );
-        assertTrue( test.toString(), test.contains( "org.apache.maven.its.mng0947:d:jar:0.1" ) );
-        assertTrue( test.toString(), test.contains( "org.apache.maven.its.mng0947:e:jar:0.1" ) );
+        assertTrue( test.toString(), test.contains( "org.apache.maven.its.mng0947:d:jar:0.1 (optional)" ) );
+        assertTrue( test.toString(), test.contains( "org.apache.maven.its.mng0947:e:jar:0.1 (optional)" ) );
         assertEquals( 3, test.size() );
     }
 
diff --git a/core-it-support/core-it-plugins/maven-it-plugin-dependency-collection/src/main/java/org/apache/maven/plugin/coreit/AbstractDependencyMojo.java b/core-it-support/core-it-plugins/maven-it-plugin-dependency-collection/src/main/java/org/apache/maven/plugin/coreit/AbstractDependencyMojo.java
index 68e6430..8b4e9ee 100644
--- a/core-it-support/core-it-plugins/maven-it-plugin-dependency-collection/src/main/java/org/apache/maven/plugin/coreit/AbstractDependencyMojo.java
+++ b/core-it-support/core-it-plugins/maven-it-plugin-dependency-collection/src/main/java/org/apache/maven/plugin/coreit/AbstractDependencyMojo.java
@@ -83,8 +83,14 @@
                 {
                     Artifact artifact = (Artifact) artifact1;
                     writer.write( artifact.getId() );
+                    String optional = "";
+                    if ( artifact.isOptional() )
+                    {
+                        optional = " (optional)";
+                        writer.write( optional );
+                    }
                     writer.newLine();
-                    getLog().info( "[MAVEN-CORE-IT-LOG]   " + artifact.getId() );
+                    getLog().info( "[MAVEN-CORE-IT-LOG]   " + artifact.getId() + optional );
                 }
             }
         }
diff --git a/core-it-support/core-it-plugins/maven-it-plugin-dependency-resolution/src/main/java/org/apache/maven/plugin/coreit/AbstractDependencyMojo.java b/core-it-support/core-it-plugins/maven-it-plugin-dependency-resolution/src/main/java/org/apache/maven/plugin/coreit/AbstractDependencyMojo.java
index 6990a6d..3ecf9b2 100644
--- a/core-it-support/core-it-plugins/maven-it-plugin-dependency-resolution/src/main/java/org/apache/maven/plugin/coreit/AbstractDependencyMojo.java
+++ b/core-it-support/core-it-plugins/maven-it-plugin-dependency-resolution/src/main/java/org/apache/maven/plugin/coreit/AbstractDependencyMojo.java
@@ -100,8 +100,14 @@
                     Artifact artifact = (Artifact) artifact1;
                     String id = getId( artifact );
                     writer.write( id );
+                    String optional = "";
+                    if ( artifact.isOptional() )
+                    {
+                        optional = " (optional)";
+                        writer.write( optional );
+                    }
                     writer.newLine();
-                    getLog().info( "[MAVEN-CORE-IT-LOG]   " + id );
+                    getLog().info( "[MAVEN-CORE-IT-LOG]   " + id + optional );
                 }
             }
         }