Use main artifact p2-maven-repository packaging and default execution

If the MavenP2SiteMojo is used as part of the p2-maven-repository
packaging and we are in the default executions do not attach an artifact
but set the main one.

tycho-p2-repository-plugin/src/main/java/org/eclipse/tycho/plugins/p2/repository/MavenP2SiteMojo.java

@@ -34,12 +34,14 @@
 
 import org.apache.commons.io.FileUtils;
 import org.apache.maven.artifact.Artifact;
+import org.apache.maven.artifact.handler.DefaultArtifactHandler;
 import org.apache.maven.artifact.resolver.ArtifactResolutionRequest;
 import org.apache.maven.artifact.resolver.ArtifactResolutionResult;
 import org.apache.maven.execution.MavenSession;
 import org.apache.maven.model.Dependency;
 import org.apache.maven.model.Plugin;
 import org.apache.maven.plugin.AbstractMojo;
+import org.apache.maven.plugin.MojoExecution;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.plugin.MojoFailureException;
 import org.apache.maven.plugins.annotations.Component;
@@ -66,6 +68,7 @@
 import org.eclipse.equinox.app.IApplication;
 import org.eclipse.equinox.p2.core.IProvisioningAgent;
 import org.eclipse.equinox.p2.repository.artifact.IArtifactRepositoryManager;
+import org.eclipse.tycho.PackagingType;
 import org.eclipse.tycho.TychoConstants;
 import org.eclipse.tycho.core.PGPService;
 import org.eclipse.tycho.p2maven.tools.TychoFeaturesAndBundlesPublisherApplication;
@@ -215,6 +218,9 @@ public class MavenP2SiteMojo extends AbstractMojo {
     @Parameter(defaultValue = INCLUDE_PGP_DEFAULT + "")
     private boolean includePGPSignature = INCLUDE_PGP_DEFAULT;
 
+    @Parameter(property = "mojoExecution", readonly = true)
+    MojoExecution execution;
+
     @Override
     public void execute() throws MojoExecutionException, MojoFailureException {
         //fetch a random service to make sure OSGi framework is there ... even if the service is (yet) not used
@@ -399,7 +405,14 @@ public void execute() throws MojoExecutionException, MojoFailureException {
         } catch (IOException e) {
             throw new MojoExecutionException("failed to create archive", e);
         }
-        projectHelper.attachArtifact(project, "zip", "p2site", destFile);
+        if (PackagingType.TYPE_P2_SITE.equals(project.getPackaging())
+                && execution.getExecutionId().startsWith("default-")) {
+            Artifact artifact = project.getArtifact();
+            artifact.setFile(destFile);
+            artifact.setArtifactHandler(new DefaultArtifactHandler("zip"));
+        } else {
+            projectHelper.attachArtifact(project, "zip", "p2site", destFile);
+        }
     }
 
     private List<String> getKeyServers() {