Merge branch 'stable-3.1'

* stable-3.1:
  Documentation: Add missing plugin in-tree testing
  Documentation: Add missing footer that links to plugin index page
  Add an empty tools/BUILD file explicitly for Bazel

Change-Id: Ib129d45ad21578869835b86ff4c9dfb85f69203c

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 7e0aae3..8d03fe2 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "968b97fa03a9d2afd760f2e8ede3d5643da390d2",
+    commit = "fbe2b2fd07c95d752dced6b8624c9d5a08e8c6c6",
     #local_path = "/home/<user>/projects/bazlets",
 )
 

src/main/java/com/googlesource/gerrit/plugins/serviceuser/PutOwner.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/serviceuser/PutOwner.java b/src/main/java/com/googlesource/gerrit/plugins/serviceuser/PutOwner.java
index 78bc448..8453e51 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/serviceuser/PutOwner.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/serviceuser/PutOwner.java
@@ -22,6 +22,7 @@
 import com.google.common.base.Strings;
 import com.google.gerrit.common.data.GroupDescription;
 import com.google.gerrit.entities.AccountGroup;
+import com.google.gerrit.entities.AccountGroup.UUID;
 import com.google.gerrit.entities.Project;
 import com.google.gerrit.extensions.annotations.PluginName;
 import com.google.gerrit.extensions.common.GroupInfo;
@@ -109,10 +110,11 @@
       db.unset(USER, rsrc.getUser().getUserName().get(), KEY_OWNER);
     } else {
       group = groups.parse(TopLevelResource.INSTANCE, IdString.fromDecoded(input.group)).getGroup();
-      if (!AccountGroup.isInternalGroup(group.getGroupUUID())) {
-        throw new MethodNotAllowedException();
+      UUID groupUUID = group.getGroupUUID();
+      if (!AccountGroup.isInternalGroup(groupUUID)) {
+        throw new MethodNotAllowedException("Group with UUID '" + groupUUID + "' is external");
       }
-      db.setString(USER, rsrc.getUser().getUserName().get(), KEY_OWNER, group.getGroupUUID().get());
+      db.setString(USER, rsrc.getUser().getUserName().get(), KEY_OWNER, groupUUID.get());
     }
     MetaDataUpdate md = metaDataUpdateFactory.create(allProjects);
     md.setMessage("Set owner for service user '" + rsrc.getUser().getUserName() + "'\n");