Detect DelegateRepository in GarbageCollection operation

When GarbageCollectCommand performs GC it expects that instance of the
repository that is passed to it is either FileRepository or
DfsRepository and throws UnsupportedOperationException otherwise.
Detect if DelegateRepository is passed as parameter and make sure that
check is performed on a delegated repository instead.

Bug: Issue 14945
Release-Notes: skip
Change-Id: I8a862ac852f5f98c09662a41234d40c26e944804
(cherry picked from commit a02af610c8ec879c79259a5d4b7a185a22311cd1)
diff --git a/java/com/google/gerrit/server/git/DelegateRepository.java b/java/com/google/gerrit/server/git/DelegateRepository.java
index 9c860c4..96b019d 100644
--- a/java/com/google/gerrit/server/git/DelegateRepository.java
+++ b/java/com/google/gerrit/server/git/DelegateRepository.java
@@ -36,6 +36,10 @@
     this.delegate = delegate;
   }
 
+  Repository delegate() {
+    return delegate;
+  }
+
   @Override
   public void create(boolean bare) throws IOException {
     delegate.create(bare);
diff --git a/java/com/google/gerrit/server/git/GarbageCollection.java b/java/com/google/gerrit/server/git/GarbageCollection.java
index 9b52f48..c37572d 100644
--- a/java/com/google/gerrit/server/git/GarbageCollection.java
+++ b/java/com/google/gerrit/server/git/GarbageCollection.java
@@ -86,7 +86,12 @@
       try (Repository repo = repoManager.openRepository(p)) {
         logGcConfiguration(p, repo, aggressive);
         print(writer, "collecting garbage for \"" + p + "\":\n");
-        GarbageCollectCommand gc = Git.wrap(repo).gc();
+        GarbageCollectCommand gc =
+            Git.wrap(
+                    repo instanceof DelegateRepository
+                        ? ((DelegateRepository) repo).delegate()
+                        : repo)
+                .gc();
         gc.setAggressive(aggressive);
         logGcInfo(p, "before:", gc.getStatistics());
         gc.setProgressMonitor(
diff --git a/javatests/com/google/gerrit/server/git/GarbageCollectionTest.java b/javatests/com/google/gerrit/server/git/GarbageCollectionTest.java
new file mode 100644
index 0000000..41b5d79
--- /dev/null
+++ b/javatests/com/google/gerrit/server/git/GarbageCollectionTest.java
@@ -0,0 +1,101 @@
+// Copyright (C) 2022 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.git;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import com.google.common.collect.ImmutableList;
+import com.google.gerrit.entities.Project;
+import com.google.gerrit.entities.Project.NameKey;
+import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.server.config.GcConfig;
+import com.google.gerrit.server.config.SitePaths;
+import com.google.gerrit.server.plugincontext.PluginContext.PluginMetrics;
+import com.google.gerrit.server.plugincontext.PluginSetContext;
+import java.io.IOException;
+import org.eclipse.jgit.errors.RepositoryNotFoundException;
+import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.lib.Repository;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnit;
+import org.mockito.junit.MockitoRule;
+
+public class GarbageCollectionTest {
+  private static final Project.NameKey FOO = Project.nameKey("foo");
+
+  @Rule public final MockitoRule mockito = MockitoJUnit.rule();
+  @Rule public TemporaryFolder temporaryFolder = new TemporaryFolder();
+
+  @Mock private GcConfig gcConfig;
+  @Mock private DelegateRepository wrapper;
+
+  private SitePaths site;
+  private Config cfg;
+
+  @Before
+  public void setup() throws Exception {
+    site = new SitePaths(temporaryFolder.newFolder().toPath());
+    site.resolve("git").toFile().mkdir();
+    cfg = new Config();
+    cfg.setString("gerrit", null, "basePath", "git");
+  }
+
+  @Test
+  public void shouldCallGcOnDelegatedRepositoryWhenDelegateRepositoryIsPassed() throws IOException {
+    // given
+    GarbageCollection objectUnderTest = prepareObjectForTesting();
+
+    // when
+    objectUnderTest.run(ImmutableList.of(FOO), false, null);
+
+    // then
+    verify(wrapper).delegate();
+  }
+
+  private GarbageCollection prepareObjectForTesting() throws IOException {
+    LocalDiskRepositoryManager repoManager = new DelegatedRepositoryManager(site, cfg, wrapper);
+    try (Repository repo = repoManager.createRepository(FOO)) {
+      assertThat(repo).isNotNull();
+    }
+    return new GarbageCollection(
+        repoManager,
+        new GarbageCollectionQueue(),
+        gcConfig,
+        new PluginSetContext<>(new DynamicSet<>(), PluginMetrics.DISABLED_INSTANCE));
+  }
+
+  private static final class DelegatedRepositoryManager extends LocalDiskRepositoryManager {
+    private final DelegateRepository wrapper;
+
+    private DelegatedRepositoryManager(SitePaths site, Config cfg, DelegateRepository wrapper) {
+      super(site, cfg);
+      this.wrapper = wrapper;
+    }
+
+    @Override
+    public Repository openRepository(NameKey name) throws RepositoryNotFoundException {
+      Repository opened = super.openRepository(name);
+      when(wrapper.delegate()).thenReturn(opened);
+      when(wrapper.getConfig()).thenReturn(opened.getConfig());
+      return wrapper;
+    }
+  }
+}