Merge changes I181742e8,If3e0a715,I9653f133,I230b7bf6

* changes:
  CreateBranch: Test that refs/meta/config branch can be created
  CreateBranch: Remove unreachable catch block for IncorrectObjectTypeException
  CreateBranch: Remove unneeded usages of final
  CreateBranch: Remove unneeded try-catch block
diff --git a/java/com/google/gerrit/server/restapi/project/CreateBranch.java b/java/com/google/gerrit/server/restapi/project/CreateBranch.java
index c15fdeb..b901057 100644
--- a/java/com/google/gerrit/server/restapi/project/CreateBranch.java
+++ b/java/com/google/gerrit/server/restapi/project/CreateBranch.java
@@ -17,7 +17,6 @@
 import static com.google.gerrit.entities.RefNames.isConfigRef;
 
 import com.google.common.base.Strings;
-import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.entities.BranchNameKey;
 import com.google.gerrit.entities.RefNames;
 import com.google.gerrit.extensions.api.projects.BranchInfo;
@@ -46,7 +45,6 @@
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
-import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.RefUpdate;
@@ -58,8 +56,6 @@
 @Singleton
 public class CreateBranch
     implements RestCollectionCreateView<ProjectResource, BranchResource, BranchInput> {
-  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
-
   private final Provider<IdentifiedUser> identifiedUser;
   private final PermissionBackend permissionBackend;
   private final GitRepositoryManager repoManager;
@@ -114,7 +110,7 @@
               + "\"");
     }
 
-    final BranchNameKey name = BranchNameKey.create(rsrc.getNameKey(), ref);
+    BranchNameKey name = BranchNameKey.create(rsrc.getNameKey(), ref);
     try (Repository repo = repoManager.openRepository(rsrc.getNameKey())) {
       ObjectId revid = RefUtil.parseBaseRevision(repo, rsrc.getNameKey(), input.revision);
       RevWalk rw = RefUtil.verifyConnected(repo, revid);
@@ -122,80 +118,71 @@
 
       if (ref.startsWith(Constants.R_HEADS)) {
         // Ensure that what we start the branch from is a commit. If we
-        // were given a tag, deference to the commit instead.
+        // were given a tag, dereference to the commit instead.
         //
-        try {
-          object = rw.parseCommit(object);
-        } catch (IncorrectObjectTypeException notCommit) {
-          throw new BadRequestException("\"" + input.revision + "\" not a commit", notCommit);
-        }
+        object = rw.parseCommit(object);
       }
 
       createRefControl.checkCreateRef(identifiedUser, repo, name, object);
 
-      try {
-        final RefUpdate u = repo.updateRef(ref);
-        u.setExpectedOldObjectId(ObjectId.zeroId());
-        u.setNewObjectId(object.copy());
-        u.setRefLogIdent(identifiedUser.get().newRefLogIdent());
-        u.setRefLogMessage("created via REST from " + input.revision, false);
-        refCreationValidator.validateRefOperation(rsrc.getName(), identifiedUser.get(), u);
-        final RefUpdate.Result result = u.update(rw);
-        switch (result) {
-          case FAST_FORWARD:
-          case NEW:
-          case NO_CHANGE:
-            referenceUpdated.fire(
-                name.project(), u, ReceiveCommand.Type.CREATE, identifiedUser.get().state());
-            break;
-          case LOCK_FAILURE:
-            if (repo.getRefDatabase().exactRef(ref) != null) {
-              throw new ResourceConflictException("branch \"" + ref + "\" already exists");
+      RefUpdate u = repo.updateRef(ref);
+      u.setExpectedOldObjectId(ObjectId.zeroId());
+      u.setNewObjectId(object.copy());
+      u.setRefLogIdent(identifiedUser.get().newRefLogIdent());
+      u.setRefLogMessage("created via REST from " + input.revision, false);
+      refCreationValidator.validateRefOperation(rsrc.getName(), identifiedUser.get(), u);
+      RefUpdate.Result result = u.update(rw);
+      switch (result) {
+        case FAST_FORWARD:
+        case NEW:
+        case NO_CHANGE:
+          referenceUpdated.fire(
+              name.project(), u, ReceiveCommand.Type.CREATE, identifiedUser.get().state());
+          break;
+        case LOCK_FAILURE:
+          if (repo.getRefDatabase().exactRef(ref) != null) {
+            throw new ResourceConflictException("branch \"" + ref + "\" already exists");
+          }
+          String refPrefix = RefUtil.getRefPrefix(ref);
+          while (!Constants.R_HEADS.equals(refPrefix)) {
+            if (repo.getRefDatabase().exactRef(refPrefix) != null) {
+              throw new ResourceConflictException(
+                  "Cannot create branch \""
+                      + ref
+                      + "\" since it conflicts with branch \""
+                      + refPrefix
+                      + "\".");
             }
-            String refPrefix = RefUtil.getRefPrefix(ref);
-            while (!Constants.R_HEADS.equals(refPrefix)) {
-              if (repo.getRefDatabase().exactRef(refPrefix) != null) {
-                throw new ResourceConflictException(
-                    "Cannot create branch \""
-                        + ref
-                        + "\" since it conflicts with branch \""
-                        + refPrefix
-                        + "\".");
-              }
-              refPrefix = RefUtil.getRefPrefix(refPrefix);
-            }
-            throw new LockFailureException(String.format("Failed to create %s", ref), u);
-          case FORCED:
-          case IO_FAILURE:
-          case NOT_ATTEMPTED:
-          case REJECTED:
-          case REJECTED_CURRENT_BRANCH:
-          case RENAMED:
-          case REJECTED_MISSING_OBJECT:
-          case REJECTED_OTHER_REASON:
-          default:
-            throw new IOException(String.format("Failed to create %s: %s", ref, result.name()));
-        }
-
-        BranchInfo info = new BranchInfo();
-        info.ref = ref;
-        info.revision = revid.getName();
-
-        if (isConfigRef(name.branch())) {
-          // Never allow to delete the meta config branch.
-          info.canDelete = null;
-        } else {
-          info.canDelete =
-              permissionBackend.currentUser().ref(name).testOrFalse(RefPermission.DELETE)
-                      && rsrc.getProjectState().statePermitsWrite()
-                  ? true
-                  : null;
-        }
-        return Response.created(info);
-      } catch (IOException err) {
-        logger.atSevere().withCause(err).log("Cannot create branch \"%s\"", name);
-        throw err;
+            refPrefix = RefUtil.getRefPrefix(refPrefix);
+          }
+          throw new LockFailureException(String.format("Failed to create %s", ref), u);
+        case FORCED:
+        case IO_FAILURE:
+        case NOT_ATTEMPTED:
+        case REJECTED:
+        case REJECTED_CURRENT_BRANCH:
+        case RENAMED:
+        case REJECTED_MISSING_OBJECT:
+        case REJECTED_OTHER_REASON:
+        default:
+          throw new IOException(String.format("Failed to create %s: %s", ref, result.name()));
       }
+
+      BranchInfo info = new BranchInfo();
+      info.ref = ref;
+      info.revision = revid.getName();
+
+      if (isConfigRef(name.branch())) {
+        // Never allow to delete the meta config branch.
+        info.canDelete = null;
+      } else {
+        info.canDelete =
+            permissionBackend.currentUser().ref(name).testOrFalse(RefPermission.DELETE)
+                    && rsrc.getProjectState().statePermitsWrite()
+                ? true
+                : null;
+      }
+      return Response.created(info);
     } catch (RefUtil.InvalidRevisionException e) {
       throw new BadRequestException("invalid revision \"" + input.revision + "\"", e);
     }
diff --git a/javatests/com/google/gerrit/acceptance/rest/project/CreateBranchIT.java b/javatests/com/google/gerrit/acceptance/rest/project/CreateBranchIT.java
index 311c264..b01a07b 100644
--- a/javatests/com/google/gerrit/acceptance/rest/project/CreateBranchIT.java
+++ b/javatests/com/google/gerrit/acceptance/rest/project/CreateBranchIT.java
@@ -50,6 +50,7 @@
 import com.google.inject.Inject;
 import java.io.IOException;
 import java.util.List;
+import org.eclipse.jgit.junit.TestRepository;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.RefUpdate;
 import org.eclipse.jgit.lib.Repository;
@@ -189,6 +190,23 @@
   }
 
   @Test
+  public void createMetaConfigBranch() throws Exception {
+    // Since the refs/meta/config branch exists by default, we must delete it before we can test
+    // creating it. Since deleting the refs/meta/config branch is not allowed through the API, we
+    // delete it directly in the remote repository.
+    try (TestRepository<Repository> repo =
+        new TestRepository<>(repoManager.openRepository(project))) {
+      repo.delete(RefNames.REFS_CONFIG);
+    }
+
+    // Create refs/meta/config branch.
+    BranchInfo created =
+        branch(BranchNameKey.create(project, RefNames.REFS_CONFIG)).create(new BranchInput()).get();
+    assertThat(created.ref).isEqualTo(RefNames.REFS_CONFIG);
+    assertThat(created.canDelete).isNull();
+  }
+
+  @Test
   public void createUserBranch_Conflict() throws Exception {
     projectOperations
         .project(allUsers)