Merge branch 'stable-2.15' into stable-2.16

* stable-2.15:
  ReceiveCommits: Fix comparison to ensure correct log message
  Set sshd.threads to at least 4.
  Add assertThrows method compatible with future JUnit 4.13
  ReceiveCommits: Bypass commit count when skip-validation is used
  Update git submodules
  Update git submodules
  Update git submodules
  Update git submodules
  Update git submodules
  Update git submodules

Change-Id: Iea0dc2d5f28c0c8e0489e7ce2bb429064ce7aca3

Documentation/config-gerrit.txt

@@ -4441,7 +4441,8 @@ Number of threads to use when executing SSH command requests.
 If additional requests are received while all threads are busy they
 are queued and serviced in a first-come-first-served order.
 +
-By default, 2x the number of CPUs available to the JVM.
+By default, 2x the number of CPUs available to the JVM (but at least 4
+threads).
 +
 [NOTE]
 When SSH daemon is enabled then this setting also defines the max number of

java/com/google/gerrit/server/config/ThreadSettingsConfig.java

@@ -28,7 +28,7 @@ public class ThreadSettingsConfig {
   @Inject
   ThreadSettingsConfig(@GerritServerConfig Config cfg) {
     int cores = Runtime.getRuntime().availableProcessors();
-    sshdThreads = cfg.getInt("sshd", "threads", 2 * cores);
+    sshdThreads = cfg.getInt("sshd", "threads", Math.max(4, 2 * cores));
     httpdMaxThreads = cfg.getInt("httpd", "maxThreads", 25);
     int defaultDatabasePoolLimit = sshdThreads + httpdMaxThreads + 2;
     databasePoolLimit = cfg.getInt("database", "poolLimit", defaultDatabasePoolLimit);

java/com/google/gerrit/server/git/receive/ReceiveCommits.java

@@ -3048,6 +3048,9 @@ class ReceiveCommits {
       int limit = receiveConfig.maxBatchCommits;
       int n = 0;
       for (RevCommit c; (c = walk.next()) != null; ) {
+        // Even if skipValidation is set, we still get here when at least one plugin
+        // commit validator requires to validate all commits. In this case, however,
+        // we don't need to check the commit limit.
         if (++n > limit && !skipValidation) {
           logger.atFine().log("Number of new commits exceeds limit of %d", limit);
           reject(

java/com/google/gerrit/testing/GerritJUnit.java

@@ -0,0 +1,67 @@
+// Copyright (C) 2019 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.testing;
+
+/** Static JUnit utility methods. */
+public class GerritJUnit {
+  /**
+   * Assert that an exception is thrown by a block of code.
+   *
+   * <p>This method is source-compatible with <a
+   * href="https://junit.org/junit4/javadoc/latest/org/junit/Assert.html#assertThrows(java.lang.Class,%20org.junit.function.ThrowingRunnable)">JUnit
+   * 4.13 beta</a>.
+   *
+   * <p>This construction is recommended by the Truth team for use in conjunction with asserting
+   * over a {@code ThrowableSubject} on the return type:
+   *
+   * <pre>
+   *   MyException e = assertThrows(MyException.class, () -> doSomething(foo));
+   *   assertThat(e).isInstanceOf(MySubException.class);
+   *   assertThat(e).hasMessageThat().contains("sub-exception occurred");
+   * </pre>
+   *
+   * @param throwableClass expected exception type.
+   * @param runnable runnable containing arbitrary code.
+   * @return exception that was thrown.
+   */
+  public static <T extends Throwable> T assertThrows(
+      Class<T> throwableClass, ThrowingRunnable runnable) {
+    try {
+      runnable.run();
+    } catch (Throwable t) {
+      if (!throwableClass.isInstance(t)) {
+        throw new AssertionError(
+            "expected "
+                + throwableClass.getName()
+                + " but "
+                + t.getClass().getName()
+                + " was thrown",
+            t);
+      }
+      @SuppressWarnings("unchecked")
+      T toReturn = (T) t;
+      return toReturn;
+    }
+    throw new AssertionError(
+        "expected " + throwableClass.getName() + " but no exception was thrown");
+  }
+
+  @FunctionalInterface
+  public interface ThrowingRunnable {
+    void run() throws Throwable;
+  }
+
+  private GerritJUnit() {}
+}

java/com/google/gerrit/testing/GerritJUnitTest.java

@@ -0,0 +1,90 @@
+// Copyright (C) 2019 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.testing;
+
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.common.truth.Truth.assert_;
+import static com.google.gerrit.testing.GerritJUnit.assertThrows;
+
+import org.junit.Test;
+
+public class GerritJUnitTest {
+  private static class MyException extends Exception {
+    private static final long serialVersionUID = 1L;
+
+    MyException(String msg) {
+      super(msg);
+    }
+  }
+
+  private static class MySubException extends MyException {
+    private static final long serialVersionUID = 1L;
+
+    MySubException(String msg) {
+      super(msg);
+    }
+  }
+
+  @Test
+  public void assertThrowsCatchesSpecifiedExceptionType() {
+    MyException e =
+        assertThrows(
+            MyException.class,
+            () -> {
+              throw new MyException("foo");
+            });
+    assertThat(e).hasMessageThat().isEqualTo("foo");
+  }
+
+  @Test
+  public void assertThrowsCatchesSubclassOfSpecifiedExceptionType() {
+    MyException e =
+        assertThrows(
+            MyException.class,
+            () -> {
+              throw new MySubException("foo");
+            });
+    assertThat(e).isInstanceOf(MySubException.class);
+    assertThat(e).hasMessageThat().isEqualTo("foo");
+  }
+
+  @Test
+  public void assertThrowsConvertsUnexpectedExceptionTypeToAssertionError() {
+    try {
+      assertThrows(
+          IllegalStateException.class,
+          () -> {
+            throw new MyException("foo");
+          });
+      assert_().fail("expected AssertionError");
+    } catch (AssertionError e) {
+      assertThat(e).hasMessageThat().contains(IllegalStateException.class.getSimpleName());
+      assertThat(e).hasMessageThat().contains(MyException.class.getSimpleName());
+      assertThat(e).hasCauseThat().isInstanceOf(MyException.class);
+      assertThat(e).hasCauseThat().hasMessageThat().isEqualTo("foo");
+    }
+  }
+
+  @Test
+  public void assertThrowsThrowsAssertionErrorWhenNothingThrown() {
+    try {
+      assertThrows(MyException.class, () -> {});
+      assert_().fail("expected AssertionError");
+    } catch (AssertionError e) {
+      assertThat(e).hasMessageThat().contains(MyException.class.getSimpleName());
+      assertThat(e).hasCauseThat().isNull();
+    }
+  }
+}

javatests/com/google/gerrit/acceptance/git/AbstractPushForReview.java

@@ -2252,6 +2252,34 @@ public abstract class AbstractPushForReview extends AbstractDaemonTest {
   @GerritConfig(name = "receive.maxBatchCommits", value = "2")
   @Test
   public void maxBatchCommits() throws Exception {
+    testMaxBatchCommits();
+  }
+
+  @GerritConfig(name = "receive.maxBatchCommits", value = "2")
+  @Test
+  public void maxBatchCommitsWithDefaultValidator() throws Exception {
+    TestValidator validator = new TestValidator();
+    RegistrationHandle handle = commitValidators.add("test-validator", validator);
+    try {
+      testMaxBatchCommits();
+    } finally {
+      handle.remove();
+    }
+  }
+
+  @GerritConfig(name = "receive.maxBatchCommits", value = "2")
+  @Test
+  public void maxBatchCommitsWithValidateAllCommitsValidator() throws Exception {
+    TestValidator validator = new TestValidator(true);
+    RegistrationHandle handle = commitValidators.add("test-validator", validator);
+    try {
+      testMaxBatchCommits();
+    } finally {
+      handle.remove();
+    }
+  }
+
+  private void testMaxBatchCommits() throws Exception {
     List<RevCommit> commits = new ArrayList<>();
     commits.addAll(initChanges(2));
     String master = "refs/heads/master";