InitJgitConfig: Git protocol v2 is enabled per default

Git wire protocol v2 is enabled in JGit per default, so there is no need
to enable it anymore in Gerrit init command. We still preserve the check
and issue a warning if protocol v2 was explicitly disabled.

Change-Id: If264e7fe2050094545d2d088ed6c1ff5b0cc0603

Documentation/config-gerrit.txt

@@ -5687,10 +5687,10 @@ and "never" suppresses expiration altogether.
 [[protocol.version]]protocol.version::
 +
 If set, the server will accept requests from a client attempting to communicate
-using the specified protocol version. Otherwise communication falls back to version 0.
-If set in file `etc/jgit.config` this option will be used for all repositories of
-the site. It can be overridden for a given repository by configuring a different
-value in the repository's `config` file.
+using the specified protocol version. Default is `2`. If set in file
+`etc/jgit.config` this option will be used for all repositories of the site.
+It can be overridden for a given repository by configuring a different value in
+the repository's `config` file.
 +
 Supported versions:
 0:: the original wire protocol.

java/com/google/gerrit/pgm/init/InitJGitConfig.java

@@ -64,22 +64,9 @@ class InitJGitConfig implements InitStep {
                 + "gc should be configured in gc config section or run as a separate process.");
       }
 
-      if (!jgitConfig
+      if (jgitConfig
           .getNames(ConfigConstants.CONFIG_PROTOCOL_SECTION)
           .contains(ConfigConstants.CONFIG_KEY_VERSION)) {
-        jgitConfig.setString(
-            ConfigConstants.CONFIG_PROTOCOL_SECTION,
-            null,
-            ConfigConstants.CONFIG_KEY_VERSION,
-            TransferConfig.ProtocolVersion.V2.version());
-        jgitConfig.save();
-        ui.error(
-            String.format(
-                "Auto-configured \"%s.%s = %s\" to activate git wire protocol version 2.",
-                ConfigConstants.CONFIG_PROTOCOL_SECTION,
-                ConfigConstants.CONFIG_KEY_VERSION,
-                TransferConfig.ProtocolVersion.V2.version()));
-      } else {
         String version =
             jgitConfig.getString(
                 ConfigConstants.CONFIG_PROTOCOL_SECTION, null, ConfigConstants.CONFIG_KEY_VERSION);

javatests/com/google/gerrit/integration/git/GitProtocolV2IT.java

@@ -42,7 +42,6 @@ import com.google.inject.Inject;
 import java.io.File;
 import java.net.InetSocketAddress;
 import org.eclipse.jgit.lib.Config;
-import org.eclipse.jgit.lib.Constants;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
@@ -98,11 +97,6 @@ public class GitProtocolV2IT extends StandaloneSiteTest {
                   .group(SystemGroupBackend.REGISTERED_USERS))
           .update();
 
-      // Set protocol.version=2 in target repository
-      execute(
-          ImmutableList.of("git", "config", "protocol.version", "2"),
-          sitePaths.site_path.resolve("git").resolve(project.get() + Constants.DOT_GIT).toFile());
-
       // Retrieve HTTP url
       String url = config.getString("gerrit", null, "canonicalweburl");
       String urlDestinationTemplate =
@@ -217,15 +211,6 @@ public class GitProtocolV2IT extends StandaloneSiteTest {
       Project.NameKey allRefsVisibleProject = Project.nameKey("all-refs-visible");
       gApi.projects().create(allRefsVisibleProject.get());
 
-      // Set protocol.version=2 in target repository
-      execute(
-          ImmutableList.of("git", "config", "protocol.version", "2"),
-          sitePaths
-              .site_path
-              .resolve("git")
-              .resolve(allRefsVisibleProject.get() + Constants.DOT_GIT)
-              .toFile());
-
       // Set up project permission to allow reading all refs
       projectOperations
           .project(allRefsVisibleProject)
@@ -280,15 +265,6 @@ public class GitProtocolV2IT extends StandaloneSiteTest {
       Project.NameKey privateProject = Project.nameKey("private-project");
       gApi.projects().create(privateProject.get());
 
-      // Set protocol.version=2 in target repository
-      execute(
-          ImmutableList.of("git", "config", "protocol.version", "2"),
-          sitePaths
-              .site_path
-              .resolve("git")
-              .resolve(privateProject.get() + Constants.DOT_GIT)
-              .toFile());
-
       // Disallow general read permissions for anonymous users
       projectOperations
           .project(allProjectsName)