[JENKINS-43507] Handle refspec aggregation correctly and GitSCM built…

… by GitSCMSource should honour refspecs on clone and not fetch tags

src/main/java/jenkins/plugins/git/GitSCMBuilder.java

@@ -37,6 +37,7 @@
 import hudson.plugins.git.browser.GitRepositoryBrowser;
 import hudson.plugins.git.extensions.GitSCMExtension;
 import hudson.plugins.git.extensions.impl.BuildChooserSetting;
+import hudson.plugins.git.extensions.impl.CloneOption;
 import hudson.scm.SCM;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -454,27 +455,52 @@ public final B withAdditionalRemote(@NonNull String remoteName, @NonNull String
      */
     @NonNull
     public final List<UserRemoteConfig> asRemoteConfigs() {
-        List<RefSpec> refSpecs = asRefSpecs();
-        List<UserRemoteConfig> result = new ArrayList<>(refSpecs.size() + additionalRemotes.size());
-        String remote = remote();
-        for (RefSpec refSpec : refSpecs) {
-            result.add(new UserRemoteConfig(remote, remoteName(), refSpec.toString(), credentialsId()));
-        }
+        List<UserRemoteConfig> result = new ArrayList<>(1 + additionalRemotes.size());
+        result.add(new UserRemoteConfig(remote(), remoteName(), joinRefSpecs(asRefSpecs()), credentialsId()));
         for (AdditionalRemote r : additionalRemotes.values()) {
-            for (RefSpec refSpec : r.asRefSpecs()) {
-                result.add(new UserRemoteConfig(r.remote(), r.remoteName(), refSpec.toString(), credentialsId()));
-            }
+            result.add(new UserRemoteConfig(r.remote(), r.remoteName(), joinRefSpecs(r.asRefSpecs()), credentialsId()));
         }
         return result;
     }
 
+    private String joinRefSpecs(List<RefSpec> refSpecs) {
+        if (refSpecs.isEmpty()) {
+            return "";
+        }
+        if (refSpecs.size() == 1) {
+            return refSpecs.get(0).toString();
+        }
+        StringBuilder result = new StringBuilder(refSpecs.size() * 50 /*most ref specs are ~50 chars*/);
+        boolean first = true;
+        for (RefSpec r : refSpecs) {
+            if (first) {
+                first = false;
+            } else {
+                result.append(' ');
+            }
+            result.append(r.toString());
+        }
+        return result.toString();
+    }
+
     /**
      * {@inheritDoc}
      */
     @NonNull
     @Override
     public GitSCM build() {
         List<GitSCMExtension> extensions = new ArrayList<>(extensions());
+        boolean foundClone = false;
+        for (GitSCMExtension e: extensions) {
+            if (e instanceof CloneOption) {
+                foundClone = true;
+                break;
+            }
+        }
+        if (!foundClone) {
+            // assume honour refspecs unless the clone option is added
+            extensions.add(new GitSCMSourceDefaults());
+        }
         SCMRevision revision = revision();
         if (revision instanceof AbstractGitSCMSource.SCMRevisionImpl) {
             // remove any conflicting BuildChooserSetting if present
@@ -577,4 +603,5 @@ public String remote() {
             return result;
         }
     }
+
 }

src/main/java/jenkins/plugins/git/GitSCMSourceDefaults.java

@@ -0,0 +1,106 @@
+/*
+ * The MIT License
+ *
+ * Copyright (c) 2017 CloudBees, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+package jenkins.plugins.git;
+
+import hudson.model.Run;
+import hudson.model.TaskListener;
+import hudson.plugins.git.GitException;
+import hudson.plugins.git.GitSCM;
+import hudson.plugins.git.extensions.GitSCMExtension;
+import java.io.IOException;
+import java.util.List;
+import org.eclipse.jgit.transport.RefSpec;
+import org.eclipse.jgit.transport.RemoteConfig;
+import org.jenkinsci.plugins.gitclient.CloneCommand;
+import org.jenkinsci.plugins.gitclient.FetchCommand;
+import org.jenkinsci.plugins.gitclient.GitClient;
+
+/**
+ * Used to reset the default clone behaviour for {@link GitSCM} instances created by {@link GitSCMBuilder}.
+ * Does not have a descriptor as we do not expect this extension to be user-visible.
+ * With this extension, we anticipate:
+ * <ul>
+ *     <li>tags will not be cloned or fetched</li>
+ *     <li>refspecs will be honoured on clone</li>
+ * </ul>
+ *
+ * @since 3.4.0
+ */
+public class GitSCMSourceDefaults extends GitSCMExtension {
+
+    /**
+     * Constructor.
+     */
+    public GitSCMSourceDefaults() {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        return o != null && getClass() == o.getClass();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public int hashCode() {
+        return getClass().hashCode();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public String toString() {
+        return "GitSCMSourceDefaults{}";
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void decorateCloneCommand(GitSCM scm, Run<?, ?> build, GitClient git, TaskListener listener,
+                                     CloneCommand cmd) throws IOException, InterruptedException, GitException {
+        listener.getLogger().println("Cloning with configured refspecs honoured and without tags");
+        RemoteConfig rc = scm.getRepositories().get(0);
+        List<RefSpec> refspecs = rc.getFetchRefSpecs();
+        cmd.refspecs(refspecs);
+        cmd.tags(false);
+    }
+
+    @Override
+    public void decorateFetchCommand(GitSCM scm, GitClient git, TaskListener listener, FetchCommand cmd)
+            throws IOException, InterruptedException, GitException {
+        listener.getLogger().println("Fetching without tags");
+        cmd.tags(false);
+    }
+}