diff --git a/Documentation/error-commit-already-exists.txt b/Documentation/error-commit-already-exists.txt
index d2b7c9d..2832c78 100644
--- a/Documentation/error-commit-already-exists.txt
+++ b/Documentation/error-commit-already-exists.txt
@@ -1,6 +1,6 @@
 = commit already exists
 
-With "commit already exists (as current patchset)" or
+With "commit(s) already exists (as current patchset)" or
 "commit already exists (in the change)" error message
 Gerrit rejects to push a commit to an existing change via
 `refs/changes/n` if the commit was already successfully
diff --git a/contrib/find-duplicate-usernames.sh b/contrib/find-duplicate-usernames.sh
new file mode 100755
index 0000000..b59e5be
--- /dev/null
+++ b/contrib/find-duplicate-usernames.sh
@@ -0,0 +1,56 @@
+#!/bin/bash
+# Copyright (C) 2021 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.
+usage() {
+  f="$(basename -- $0)"
+  cat <<EOF
+Usage:
+    cd /path/to/All-Users.git
+    "$f [username|gerrit|external]"
+
+This script finds duplicate usernames only differing in case in the given
+account schema ("username", "gerrit" or "external") and their respective accountIds.
+EOF
+  exit 1
+}
+
+if [[ "$#" -ne "1" ]] || ! [[ "$1" =~ ^(gerrit|username|external)$ ]]; then
+  usage
+fi
+
+# 1. find lines with user name and subsequent line in external-ids notes branch
+#    example output of git grep -A1 "\[externalId \"username:" refs/meta/external-ids:
+#    refs/meta/external-ids:00/1d/abd037e437f71d42134e6ad532a06948a2ba:[externalId "username:johndoe"]
+#    refs/meta/external-ids:00/1d/abd037e437f71d42134e6ad532a06948a2ba-      accountId = 1000815
+#    --
+#    refs/meta/external-ids:00/1f/0270fc2a6fc3a2439c454c8ab0c75323fdb0:[externalId "username:JohnDoe"]
+#    refs/meta/external-ids:00/1f/0270fc2a6fc3a2439c454c8ab0c75323fdb0-      accountId = 1000816
+#    --
+# 2. remove group separators
+# 3. remove line break between user name and accountId lines
+# 4. unify separators to ":"
+# 5. cut on ":", select username and accountId fields
+# 6. sort case-insensitive
+# 7. flip columns
+# 8. uniq case-insensitive, only show duplicates, avoid comparing first field
+# 9. flip columns back
+git grep -A1 "\[externalId \"$1:" refs/meta/external-ids \
+  | sed -E "/$1/,/accountId/!d" \
+  | paste -d ' ' - - \
+  | tr \"= : \
+  | cut -d: --output-delimiter="" -f 5,8 \
+  | sort -f \
+  | sed -E "s/(.*) (.*)/\2 \1/" \
+  | uniq -Di -f1 \
+  | sed -E "s/(.*) (.*)/\2 \1/"
diff --git a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/AbandonChange.scala b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/AbandonChange.scala
index 51bcb9e..d387a3e 100644
--- a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/AbandonChange.scala
+++ b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/AbandonChange.scala
@@ -43,9 +43,9 @@
             numbersCopy = createChange.get.numbers.clone()
           }
         }
-        session.set("number", numbersCopy.dequeue())
+        session.set(numberKey, numbersCopy.dequeue())
       })
-      .exec(http(uniqueName).post("${url}${number}/abandon"))
+      .exec(http(uniqueName).post("${url}${" + numberKey + "}/abandon"))
 
   private val createProject = new CreateProject(projectName)
   private val deleteProject = new DeleteProject(projectName)
diff --git a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/ApproveChange.scala b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/ApproveChange.scala
index 5e4f671..9a91153 100644
--- a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/ApproveChange.scala
+++ b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/ApproveChange.scala
@@ -40,13 +40,13 @@
           if (numbersCopy.isEmpty) {
             numbersCopy = createChange.get.numbers.clone()
           }
-          session.set("number", numbersCopy.dequeue())
+          session.set(numberKey, numbersCopy.dequeue())
         } else {
           session
         }
       })
       .exec(http(uniqueName)
-          .post("${url}${number}/revisions/current/review")
+          .post("${url}${" + numberKey + "}/revisions/current/review")
           .body(ElFileBody(body)).asJson)
 
   setUp(
diff --git a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/CreateChange.scala b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/CreateChange.scala
index b28edb5..fb41075 100644
--- a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/CreateChange.scala
+++ b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/CreateChange.scala
@@ -24,7 +24,6 @@
 
 class CreateChange extends ProjectSimulation {
   private val data: FeederBuilder = jsonFile(resource).convert(keys).circular
-  private val numberKey = "_number"
   private val weightPerUser = 0.1
   private var createBranch: Option[CreateBranch] = None
   private var branchesCopy: mutable.Queue[String] = mutable.Queue[String]()
@@ -58,7 +57,7 @@
       })
       .exec(httpRequest
           .body(ElFileBody(body)).asJson
-          .check(regex("\"" + numberKey + "\":(\\d+),").saveAs(numberKey)))
+          .check(regex("\"_" + numberKey + "\":(\\d+),").saveAs(numberKey)))
       .exec(session => {
         number = session(numberKey).as[Int]
         numbers += number
diff --git a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/DeleteChange.scala b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/DeleteChange.scala
index e47108f..743219f 100644
--- a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/DeleteChange.scala
+++ b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/DeleteChange.scala
@@ -34,12 +34,12 @@
       .feed(data)
       .exec(session => {
         if (createChange.nonEmpty) {
-          session.set("number", createChange.get.numbers.dequeue())
+          session.set(numberKey, createChange.get.numbers.dequeue())
         } else {
           session
         }
       })
-      .exec(http(uniqueName).delete("${url}${number}"))
+      .exec(http(uniqueName).delete("${url}${" + numberKey + "}"))
 
   setUp(
     test.inject(
diff --git a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/GerritSimulation.scala b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/GerritSimulation.scala
index b11c87c..c199dd9 100644
--- a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/GerritSimulation.scala
+++ b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/GerritSimulation.scala
@@ -23,6 +23,8 @@
 class GerritSimulation extends Simulation {
   implicit val conf: GatlingGitConfiguration = GatlingGitConfiguration()
 
+  protected val numberKey: String = "number"
+
   private val packageName = getClass.getPackage.getName
   private val path = packageName.replaceAllLiterally(".", "/")
 
@@ -64,9 +66,9 @@
   protected val keys: PartialFunction[(String, Any), Any] = {
     case ("entries", entries) =>
       replaceProperty("projects_entries", "1", entries.toString)
-    case ("number", number) =>
-      val precedes = replaceKeyWith("_number", 0, number.toString)
-      replaceProperty("number", 1, precedes)
+    case (`numberKey`, number) =>
+      val precedes = replaceKeyWith("_" + numberKey, 0, number.toString)
+      replaceProperty(numberKey, 1, precedes)
     case ("parent", parent) =>
       replaceProperty("parent", "All-Projects", parent.toString)
     case ("project", project) =>
@@ -90,6 +92,11 @@
   }
 
   protected def replaceProperty(term: String, default: Any, in: String): String = {
+    val value = getProperty(term, default)
+    replaceKeyWith(term, value, in)
+  }
+
+  protected def getProperty(term: String, default: Any): String = {
     val property = packageName + "." + term
     var value = default
     default match {
@@ -101,7 +108,7 @@
       case _: Integer =>
         value = Integer.getInteger(property, default.asInstanceOf[Integer])
     }
-    replaceKeyWith(term, value, in)
+    value.toString
   }
 
   protected def replaceKeyWith(term: String, value: Any, in: String): String = {
diff --git a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/RestoreChange.scala b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/RestoreChange.scala
index b952670..81096b0 100644
--- a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/RestoreChange.scala
+++ b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/RestoreChange.scala
@@ -35,9 +35,9 @@
         if (numbersCopy.isEmpty) {
           numbersCopy = createChange.numbers.clone()
         }
-        session.set("number", numbersCopy.dequeue())
+        session.set(numberKey, numbersCopy.dequeue())
       }
-      ).exec(http(uniqueName).post("${url}${number}/restore"))
+      ).exec(http(uniqueName).post("${url}${" + numberKey + "}/restore"))
 
   private val createProject = new CreateProject(projectName)
   private val createChange = new CreateChange(projectName)
diff --git a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/SubmitChange.scala b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/SubmitChange.scala
index 067496a..20be28a 100644
--- a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/SubmitChange.scala
+++ b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/SubmitChange.scala
@@ -36,9 +36,9 @@
   val test: ScenarioBuilder = scenario(uniqueName)
       .feed(data)
       .exec(session => {
-        session.set("number", createChange.number)
+        session.set(numberKey, createChange.number)
       })
-      .exec(http(uniqueName).post("${url}${number}/submit"))
+      .exec(http(uniqueName).post("${url}${" + numberKey + "}/submit"))
 
   private val createProject = new CreateProject(projectName)
   private val approveChange = new ApproveChange(createChange)
diff --git a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/SubmitChangeInBranch.scala b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/SubmitChangeInBranch.scala
index 1b88503..9e1431b 100644
--- a/e2e-tests/src/test/scala/com/google/gerrit/scenarios/SubmitChangeInBranch.scala
+++ b/e2e-tests/src/test/scala/com/google/gerrit/scenarios/SubmitChangeInBranch.scala
@@ -35,9 +35,9 @@
         if (changesCopy.isEmpty) {
           changesCopy = createChange.numbers.clone()
         }
-        session.set("number", changesCopy.dequeue())
+        session.set(numberKey, changesCopy.dequeue())
       })
-      .exec(http(uniqueName).post("${url}${number}/submit"))
+      .exec(http(uniqueName).post("${url}${" + numberKey + "}/submit"))
 
   private val createProject = new CreateProject(projectName)
   private val createBranch = new CreateBranch(projectName)
diff --git a/polygerrit-ui/app/behaviors/gr-access-behavior/gr-access-behavior.html b/polygerrit-ui/app/behaviors/gr-access-behavior/gr-access-behavior.html
index 0c75c44..fedefc6 100644
--- a/polygerrit-ui/app/behaviors/gr-access-behavior/gr-access-behavior.html
+++ b/polygerrit-ui/app/behaviors/gr-access-behavior/gr-access-behavior.html
@@ -88,10 +88,6 @@
             id: 'owner',
             name: 'Owner',
           },
-          publishDrafts: {
-            id: 'publishDrafts',
-            name: 'Publish Drafts',
-          },
           push: {
             id: 'push',
             name: 'Push',
diff --git a/polygerrit-ui/app/elements/admin/gr-repo-list/gr-repo-list.js b/polygerrit-ui/app/elements/admin/gr-repo-list/gr-repo-list.js
index 0eaa496..5de844f 100644
--- a/polygerrit-ui/app/elements/admin/gr-repo-list/gr-repo-list.js
+++ b/polygerrit-ui/app/elements/admin/gr-repo-list/gr-repo-list.js
@@ -125,7 +125,7 @@
           .then(repos => {
             // Late response.
             if (filter !== this._filter || !repos) { return; }
-            this._repos = repos;
+            this._repos = repos.filter(repo => repo.name.includes(filter));
             this._loading = false;
           });
     },
diff --git a/polygerrit-ui/app/elements/admin/gr-repo-list/gr-repo-list_test.html b/polygerrit-ui/app/elements/admin/gr-repo-list/gr-repo-list_test.html
index c77592c..625312d 100644
--- a/polygerrit-ui/app/elements/admin/gr-repo-list/gr-repo-list_test.html
+++ b/polygerrit-ui/app/elements/admin/gr-repo-list/gr-repo-list_test.html
@@ -40,6 +40,7 @@
   const repoGenerator = () => {
     return {
       id: `test${++counter}`,
+      name: `test`,
       state: 'ACTIVE',
       web_links: [
         {
diff --git a/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header.js b/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header.js
index 773ad68..ab9b70e 100644
--- a/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header.js
+++ b/polygerrit-ui/app/elements/core/gr-main-header/gr-main-header.js
@@ -224,7 +224,7 @@
         });
         if (m.name in topMenuLinks) {
           items.forEach(link => { topMenuLinks[m.name].push(link); });
-        } else {
+        } else if (items.length > 0) {
           links.push({
             title: m.name,
             links: topMenuLinks[m.name] = items,