Add head name property in MercurialSCM

src/main/java/hudson/plugins/mercurial/MercurialSCM.java

@@ -151,6 +151,8 @@
     @Deprecated
     private String branch;
 
+    private String headName = "default";
+
     /** Slash-separated subdirectory of the workspace in which the repository will be kept; null for top level. */
     private String subdir;
 
@@ -300,6 +302,14 @@
         this.revision = Util.fixEmpty(revision) == null ? "default" : revision;
     }
 
+    public @NonNull String getHeadName() {
+        return headName;
+    }
+
+    public final void setHeadName(@NonNull String headName) {
+        this.headName = Util.fixEmpty(headName) == null ? "default" : headName;
+    }
+
     @Deprecated
     public String getBranch() {
         if (revisionType != RevisionType.BRANCH) {

src/main/java/hudson/plugins/mercurial/MercurialSCMBuilder.java

@@ -115,10 +115,13 @@
         MercurialSCM result = new MercurialSCM(source());
         if (revision instanceof MercurialSCMSource.MercurialRevision) {
             result.setRevisionType(MercurialSCM.RevisionType.CHANGESET);
-            result.setRevision(((MercurialSCMSource.MercurialRevision) revision).getHash());
+            MercurialSCMSource.MercurialRevision mercurialRevision = (MercurialSCMSource.MercurialRevision) revision;
+            result.setRevision(mercurialRevision.getHash());
+            result.setHeadName(mercurialRevision.getHead().getName());
         } else {
             result.setRevisionType(MercurialSCM.RevisionType.BRANCH);
             result.setRevision(head().getName());
+            result.setHeadName(head().getName());
         }
         result.setBrowser(browser());
         result.setClean(clean());

src/test/java/hudson/plugins/mercurial/MercurialSCMBuilderTest.java

@@ -0,0 +1,88 @@
+package hudson.plugins.mercurial;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.Map;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import hudson.FilePath;
+import hudson.tools.ToolProperty;
+import hudson.util.LogTaskListener;
+import hudson.util.StreamTaskListener;
+import jenkins.scm.api.SCMHead;
+import jenkins.scm.api.SCMHeadObserver;
+import jenkins.scm.api.SCMRevision;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.jvnet.hudson.test.JenkinsRule;
+
+import static org.junit.Assert.assertEquals;
+
+public class MercurialSCMBuilderTest {
+    @Rule
+    public JenkinsRule j = new JenkinsRule();
+    @Rule
+    public MercurialRule m = new MercurialRule(j);
+    @Rule
+    public TemporaryFolder tmp = new TemporaryFolder();
+
+    private static LogTaskListener listener;
+    private static MercurialSCMSource mercurialSCMSource;
+
+    @Before
+    public void prepareEnvironment() throws Exception {
+        String instName = "caching";
+        MercurialInstallation installation = new MercurialInstallation(instName, "", "hg", false, true, null, false, null,
+                Collections.<ToolProperty<?>>emptyList());
+        listener = new LogTaskListener(Logger.getLogger(MercurialSCMSourceTest.class.getName()), Level.INFO);
+        j.jenkins.getDescriptorByType(MercurialInstallation.DescriptorImpl.class).setInstallations(installation);
+        FilePath repo = new FilePath(tmp.getRoot());
+        installation.forNode(j.jenkins, StreamTaskListener.fromStdout());
+        m.hg(repo, "init");
+        repo.child("file").write("initial content", "UTF-8");
+        m.hg(repo, "commit", "--addremove", "--message=initial");
+        m.hg(repo, "tag", "version-1.0");
+        m.hg(repo, "branch", "my-branch");
+        repo.child("file2").write("content in branch", "UTF-8");
+        m.hg(repo, "commit", "--addremove", "--message=branch");
+        m.hg(repo, "tag", "version-1.1");
+
+        installation.forNode(j.jenkins, StreamTaskListener.fromStdout());
+        mercurialSCMSource = new MercurialSCMSource(null, instName, tmp.getRoot().toURI().toURL().toString(), null, null, null, null, null, true);
+    }
+
+    @Test
+    public void headNameEquals() throws IOException, InterruptedException {
+        Map<SCMHead, SCMRevision> result = mercurialSCMSource.fetch(null, SCMHeadObserver.collect(), null, null).result();
+        for (Map.Entry<SCMHead, SCMRevision> entry : result.entrySet()) {
+            MercurialSCM mercurialSCM = new MercurialSCMBuilder(entry.getKey(), entry.getValue(), "", "")
+                    .build();
+            assertEquals(MercurialSCM.RevisionType.CHANGESET, mercurialSCM.getRevisionType());
+            assertEquals(entry.getValue().getHead().getName(), mercurialSCM.getHeadName());
+            assertEquals(entry.getKey().getName(), mercurialSCM.getHeadName());
+        }
+    }
+
+    @Test
+    public void headNameDefault() throws IOException, InterruptedException {
+        SCMRevision revision = mercurialSCMSource.fetch("version-1.0", listener, null);
+        MercurialSCM mercurialSCM = new MercurialSCMBuilder(revision.getHead(), revision, "", "")
+                .build();
+        assertEquals(MercurialSCM.RevisionType.CHANGESET, mercurialSCM.getRevisionType());
+        assertEquals("default", mercurialSCM.getHeadName());
+        assertEquals(revision.getHead().getName(), mercurialSCM.getHeadName());
+    }
+
+    @Test
+    public void headNameNonDefault() throws IOException, InterruptedException {
+        SCMRevision revision = mercurialSCMSource.fetch("version-1.1", listener, null);
+        MercurialSCM mercurialSCM = new MercurialSCMBuilder(revision.getHead(), revision, "", "")
+                .build();
+        assertEquals(MercurialSCM.RevisionType.CHANGESET, mercurialSCM.getRevisionType());
+        assertEquals("my-branch", mercurialSCM.getHeadName());
+        assertEquals(revision.getHead().getName(), mercurialSCM.getHeadName());
+    }
+}