From 994fe17fb0e894d56925d88368f712e268a47c64 Mon Sep 17 00:00:00 2001
From: Alpar Torok <torokalpar@gmail.com>
Date: Wed, 6 Mar 2019 15:55:50 +0200
Subject: [PATCH] Forward port bwc version fix from 7.x

While working on a backport I realized that #38593 was merged in `7.x`
and missing in master.
We need this or it will cause trouble again when we bump majors next
time.
---
 .../gradle/VersionCollection.java             | 24 +++++++++++++++++--
 .../gradle/VersionCollectionTests.java        |  4 ++--
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/buildSrc/src/main/java/org/elasticsearch/gradle/VersionCollection.java b/buildSrc/src/main/java/org/elasticsearch/gradle/VersionCollection.java
index dc981a2694e4e..703a38fca48e7 100644
--- a/buildSrc/src/main/java/org/elasticsearch/gradle/VersionCollection.java
+++ b/buildSrc/src/main/java/org/elasticsearch/gradle/VersionCollection.java
@@ -223,7 +223,12 @@ private String getBranchFor(Version version) {
             case ":distribution":
                 return "master";
             case ":distribution:bwc:minor":
-                return version.getMajor() + ".x";
+                final Version latestInMajor = getLatestVersionByKey(groupByMajor, version.getMajor());
+                if (latestInMajor.getMinor() == version.getMinor()) {
+                    return version.getMajor() + ".x";
+                } else {
+                    return version.getMajor() + "." + version.getMinor();
+                }
             case ":distribution:bwc:staged":
             case ":distribution:bwc:maintenance":
             case ":distribution:bwc:bugfix":
@@ -239,7 +244,15 @@ public List<Version> getUnreleased() {
         unreleased.add(currentVersion);
 
         // the tip of the previous major is unreleased for sure, be it a minor or a bugfix
-        unreleased.add(getLatestVersionByKey(this.groupByMajor, currentVersion.getMajor() - 1));
+        final Version latestOfPreviousMajor = getLatestVersionByKey(this.groupByMajor, currentVersion.getMajor() - 1);
+        unreleased.add(latestOfPreviousMajor);
+        if (latestOfPreviousMajor.getRevision() == 0) {
+            // if the previous major is a x.y.0 release, then the tip of the minor before that (y-1) is also unreleased
+            final Version previousMinor = getLatestInMinor(latestOfPreviousMajor.getMajor(), latestOfPreviousMajor.getMinor() - 1);
+            if (previousMinor != null) {
+                unreleased.add(previousMinor);
+            }
+        }
 
         final Map<Integer, List<Version>> groupByMinor = getReleasedMajorGroupedByMinor();
         int greatestMinor = groupByMinor.keySet().stream().max(Integer::compareTo).orElse(0);
@@ -267,6 +280,13 @@ public List<Version> getUnreleased() {
         );
     }
 
+    private Version getLatestInMinor(int major, int minor) {
+        return groupByMajor.get(major).stream()
+            .filter(v -> v.getMinor() == minor)
+            .max(Version::compareTo)
+            .orElse(null);
+    }
+
     private Version getLatestVersionByKey(Map<Integer, List<Version>> groupByMajor, int key) {
         return groupByMajor.getOrDefault(key, emptyList()).stream()
             .max(Version::compareTo)
diff --git a/buildSrc/src/test/java/org/elasticsearch/gradle/VersionCollectionTests.java b/buildSrc/src/test/java/org/elasticsearch/gradle/VersionCollectionTests.java
index 03e08cb3ffe45..fa0e261e4c8cb 100644
--- a/buildSrc/src/test/java/org/elasticsearch/gradle/VersionCollectionTests.java
+++ b/buildSrc/src/test/java/org/elasticsearch/gradle/VersionCollectionTests.java
@@ -298,7 +298,7 @@ public void testGetBranch() {
             getVersionCollection("6.4.2")
         );
         assertUnreleasedBranchNames(
-            asList("5.6", "6.4", "6.x"),
+            asList("5.6", "6.4", "6.5"),
             getVersionCollection("6.6.0")
         );
         assertUnreleasedBranchNames(
@@ -329,7 +329,7 @@ public void testGetGradleProjectPath() {
             getVersionCollection("8.0.0")
         );
         assertUnreleasedGradleProjectPaths(
-            asList(":distribution:bwc:staged", ":distribution:bwc:minor"),
+            asList(":distribution:bwc:maintenance", ":distribution:bwc:staged", ":distribution:bwc:minor"),
             getVersionCollection("7.1.0")
         );
     }