Merge branch 'stable-3.0' into stable-3.1

* stable-3.0:
  Elasticsearch: Remove support for EOL 6.7 version
  Update the recommended buildifier version to 3.5.0
  Remove unused Documentation/config-login-register.txt

From this branch, the downstream dev-contributing.txt content moved to
dev-crafting-changes.txt.

Change-Id: I2578843a42f29e09f90ee2918bd5206e3dd273db
diff --git a/java/com/google/gerrit/elasticsearch/ElasticQueryAdapter.java b/java/com/google/gerrit/elasticsearch/ElasticQueryAdapter.java
index 7233682..779d433 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticQueryAdapter.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticQueryAdapter.java
@@ -14,7 +14,7 @@
 
 package com.google.gerrit.elasticsearch;
 
-import static com.google.gerrit.elasticsearch.ElasticVersion.V6_7;
+import static com.google.gerrit.elasticsearch.ElasticVersion.V6_8;
 
 public class ElasticQueryAdapter {
   static final String V6_TYPE = "_doc";
@@ -41,13 +41,15 @@
     this.defaultNumberOfShards = version.isV7OrLater() ? 1 : 5;
     this.versionDiscoveryUrl = version.isV6OrLater() ? "/%s*" : "/%s*/_aliases";
     this.searchFilteringName = "_source";
-    this.indicesExistParams =
-        version.isAtLeastMinorVersion(V6_7) ? INDICES + "&" + INCLUDE_TYPE : INDICES;
     this.exactFieldType = "keyword";
     this.stringFieldType = "text";
     this.indexProperty = "true";
     this.rawFieldsKey = "_source";
-    this.includeTypeNameParam = version.isAtLeastMinorVersion(V6_7) ? "?" + INCLUDE_TYPE : "";
+
+    // Since v6.7 (end-of-life), in fact, for these two parameters:
+    this.indicesExistParams =
+        version.isAtLeastMinorVersion(V6_8) ? INDICES + "&" + INCLUDE_TYPE : INDICES;
+    this.includeTypeNameParam = version.isAtLeastMinorVersion(V6_8) ? "?" + INCLUDE_TYPE : "";
   }
 
   public String searchFilteringName() {
diff --git a/java/com/google/gerrit/elasticsearch/ElasticVersion.java b/java/com/google/gerrit/elasticsearch/ElasticVersion.java
index c79a25e..b3f1471 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticVersion.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticVersion.java
@@ -18,7 +18,6 @@
 import java.util.regex.Pattern;
 
 public enum ElasticVersion {
-  V6_7("6.7.*"),
   V6_8("6.8.*"),
   V7_0("7.0.*"),
   V7_1("7.1.*"),
diff --git a/javatests/com/google/gerrit/elasticsearch/ElasticContainer.java b/javatests/com/google/gerrit/elasticsearch/ElasticContainer.java
index 1a43269..86829b9 100644
--- a/javatests/com/google/gerrit/elasticsearch/ElasticContainer.java
+++ b/javatests/com/google/gerrit/elasticsearch/ElasticContainer.java
@@ -38,8 +38,6 @@
 
   private static String getImageName(ElasticVersion version) {
     switch (version) {
-      case V6_7:
-        return "blacktop/elasticsearch:6.7.2";
       case V6_8:
         return "blacktop/elasticsearch:6.8.12";
       case V7_0:
diff --git a/javatests/com/google/gerrit/elasticsearch/ElasticVersionTest.java b/javatests/com/google/gerrit/elasticsearch/ElasticVersionTest.java
index b9d5313..9325a1b 100644
--- a/javatests/com/google/gerrit/elasticsearch/ElasticVersionTest.java
+++ b/javatests/com/google/gerrit/elasticsearch/ElasticVersionTest.java
@@ -22,9 +22,6 @@
 public class ElasticVersionTest {
   @Test
   public void supportedVersion() throws Exception {
-    assertThat(ElasticVersion.forVersion("6.7.0")).isEqualTo(ElasticVersion.V6_7);
-    assertThat(ElasticVersion.forVersion("6.7.1")).isEqualTo(ElasticVersion.V6_7);
-
     assertThat(ElasticVersion.forVersion("6.8.0")).isEqualTo(ElasticVersion.V6_8);
     assertThat(ElasticVersion.forVersion("6.8.1")).isEqualTo(ElasticVersion.V6_8);
 
@@ -70,7 +67,6 @@
 
   @Test
   public void atLeastMinorVersion() throws Exception {
-    assertThat(ElasticVersion.V6_7.isAtLeastMinorVersion(ElasticVersion.V6_7)).isTrue();
     assertThat(ElasticVersion.V6_8.isAtLeastMinorVersion(ElasticVersion.V6_8)).isTrue();
     assertThat(ElasticVersion.V7_0.isAtLeastMinorVersion(ElasticVersion.V6_8)).isFalse();
     assertThat(ElasticVersion.V7_1.isAtLeastMinorVersion(ElasticVersion.V6_8)).isFalse();
@@ -85,7 +81,6 @@
 
   @Test
   public void version6OrLater() throws Exception {
-    assertThat(ElasticVersion.V6_7.isV6OrLater()).isTrue();
     assertThat(ElasticVersion.V6_8.isV6OrLater()).isTrue();
     assertThat(ElasticVersion.V7_0.isV6OrLater()).isTrue();
     assertThat(ElasticVersion.V7_1.isV6OrLater()).isTrue();
@@ -100,7 +95,6 @@
 
   @Test
   public void version7OrLater() throws Exception {
-    assertThat(ElasticVersion.V6_7.isV7OrLater()).isFalse();
     assertThat(ElasticVersion.V6_8.isV7OrLater()).isFalse();
     assertThat(ElasticVersion.V7_0.isV7OrLater()).isTrue();
     assertThat(ElasticVersion.V7_1.isV7OrLater()).isTrue();