Change verboseSuperprojectUpdate config into a tri-state Enum

verboseSuperprojectUpdate was a boolean config option that either do not
include anything (false state) or include the full commit messages(true
state) from all related submodule changes. Add a third state called
SUBJECT_ONLY that only include the subjects of the commits from the
change history. Also set the default to be SUBJECT_ONLY.

Change-Id: I6baa16180c31f36ed3d61930834470c3c27387ed

Documentation/config-gerrit.txt

@@ -3932,10 +3932,16 @@ It can contain placeholders for the groups matched by the
 [[submodule.verbosesuperprojectupdate]]submodule.verboseSuperprojectUpdate::
 +
 When using link:user-submodules.html#automatic_update[automatic superproject updates]
-this option will determine if the submodule commit messages are included into
+this option will determine how the submodule commit messages are included into
 the commit message of the superproject update.
 +
-By default this is true.
+If `FALSE`, will not include any commit messages for the gitlink update.
++
+If `SUBJECT_ONLY`, will include only the commit subjects.
++
+If `TRUE`, will include full commit messages.
++
+By default this is `TRUE`.
 
 [[submodule.enableSuperProjectSubscriptions]]submodule.enableSuperProjectSubscriptions::
 +

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/git/SubmoduleSubscriptionsIT.java

@@ -201,6 +201,35 @@ public class SubmoduleSubscriptionsIT extends AbstractSubmoduleSubscription {
         "Update git submodules\n\n");
   }
 
+  @Test
+  @GerritConfig(name = "submodule.verboseSuperprojectUpdate", value = "SUBJECT_ONLY")
+  public void testSubmoduleSubjectCommitMessage() throws Exception {
+    TestRepository<?> superRepo = createProjectWithPush("super-project");
+    TestRepository<?> subRepo = createProjectWithPush("subscribed-to-project");
+    allowSubmoduleSubscription("subscribed-to-project", "refs/heads/master",
+        "super-project", "refs/heads/master");
+
+    pushChangeTo(subRepo, "master");
+    createSubmoduleSubscription(superRepo, "master",
+        "subscribed-to-project", "master");
+    ObjectId subHEAD = pushChangeTo(subRepo, "master");
+
+    // The first update doesn't include the rev log
+    RevWalk rw = subRepo.getRevWalk();
+    expectToHaveCommitMessage(superRepo, "master",
+        "Update git submodules\n\n" +
+            "* Update " + name("subscribed-to-project") + " from branch 'master'");
+
+    // The next commit should generate only its commit message,
+    // omitting previous commit logs
+    subHEAD = pushChangeTo(subRepo, "master");
+    RevCommit subCommitMsg = rw.parseCommit(subHEAD);
+    expectToHaveCommitMessage(superRepo, "master",
+        "Update git submodules\n\n" +
+            "* Update " + name("subscribed-to-project") + " from branch 'master'"
+            + "\n  - " + subCommitMsg.getShortMessage());
+  }
+
   @Test
   public void testSubmoduleCommitMessage() throws Exception {
     TestRepository<?> superRepo = createProjectWithPush("super-project");

gerrit-server/src/main/java/com/google/gerrit/server/config/VerboseSuperprojectUpdate.java

@@ -0,0 +1,29 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed 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 com.google.gerrit.server.config;
+
+/**
+ * Verbosity level of the commit message for submodule subscriptions.
+ */
+public enum VerboseSuperprojectUpdate {
+  /** Do not include any commit messages for the gitlink update. */
+  FALSE,
+
+  /** Only include the commit subjects. */
+  SUBJECT_ONLY,
+
+  /** Include full commit messages. */
+  TRUE
+}

gerrit-server/src/main/java/com/google/gerrit/server/git/SubmoduleOp.java

@@ -26,6 +26,7 @@ import com.google.gerrit.reviewdb.client.RefNames;
 import com.google.gerrit.reviewdb.client.SubmoduleSubscription;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.config.GerritServerConfig;
+import com.google.gerrit.server.config.VerboseSuperprojectUpdate;
 import com.google.gerrit.server.git.BatchUpdate.Listener;
 import com.google.gerrit.server.git.BatchUpdate.RepoContext;
 import com.google.gerrit.server.git.MergeOpRepoManager.OpenRepo;
@@ -99,7 +100,7 @@ public class SubmoduleOp {
   private final PersonIdent myIdent;
   private final ProjectCache projectCache;
   private final ProjectState.Factory projectStateFactory;
-  private final boolean verboseSuperProject;
+  private final VerboseSuperprojectUpdate verboseSuperProject;
   private final boolean enableSuperProjectSubscriptions;
   private final Multimap<Branch.NameKey, SubmoduleSubscription> targets;
   private final Set<Branch.NameKey> updatedBranches;
@@ -121,8 +122,9 @@ public class SubmoduleOp {
     this.myIdent = myIdent;
     this.projectCache = projectCache;
     this.projectStateFactory = projectStateFactory;
-    this.verboseSuperProject = cfg.getBoolean("submodule",
-        "verboseSuperprojectUpdate", true);
+    this.verboseSuperProject =
+        cfg.getEnum("submodule", null, "verboseSuperprojectUpdate",
+            VerboseSuperprojectUpdate.TRUE);
     this.enableSuperProjectSubscriptions = cfg.getBoolean("submodule",
         "enableSuperProjectSubscriptions", true);
     this.orm = orm;
@@ -365,7 +367,7 @@ public class SubmoduleOp {
     commit.setTreeId(newTreeId);
     commit.setParentId(currentCommit);
     StringBuilder commitMsg = new StringBuilder("Update git submodules\n\n");
-    if (verboseSuperProject) {
+    if (verboseSuperProject != VerboseSuperprojectUpdate.FALSE) {
       commitMsg.append(msgbuf);
     }
     commit.setMessage(commitMsg.toString());
@@ -405,7 +407,8 @@ public class SubmoduleOp {
     CommitBuilder commit = new CommitBuilder();
     commit.setTreeId(newTreeId);
     commit.setParentIds(currentCommit.getParents());
-    if (verboseSuperProject) {
+    if (verboseSuperProject != VerboseSuperprojectUpdate.FALSE) {
+      //TODO:czhen handle cherrypick footer
       commit.setMessage(
           currentCommit.getFullMessage() + "\n\n*submodules:\n" + msgbuf.toString());
     } else {
@@ -463,7 +466,7 @@ public class SubmoduleOp {
       }
     });
 
-    if (verboseSuperProject) {
+    if (verboseSuperProject != VerboseSuperprojectUpdate.FALSE) {
       createSubmoduleCommitMsg(msgbuf, s, subOr, newCommit, oldCommit);
     }
     subOr.rw.parseBody(newCommit);
@@ -487,7 +490,11 @@ public class SubmoduleOp {
       subOr.rw.markUninteresting(oldCommit);
       for (RevCommit c : subOr.rw) {
         subOr.rw.parseBody(c);
-        msgbuf.append("\n  - " + c.getFullMessage().replace("\n", "\n    "));
+        if (verboseSuperProject == VerboseSuperprojectUpdate.SUBJECT_ONLY) {
+          msgbuf.append("\n  - " + c.getShortMessage());
+        } else if (verboseSuperProject == VerboseSuperprojectUpdate.TRUE) {
+          msgbuf.append("\n  - " + c.getFullMessage().replace("\n", "\n    "));
+        }
       }
     } catch (IOException e) {
       throw new SubmoduleException("Could not perform a revwalk to "