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new file mode 100644
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--- /dev/null
+++ b/Documentation/images/user-review-ui-side-by-side-diff-screen-preferences.png
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new file mode 100644
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--- /dev/null
+++ b/Documentation/images/user-review-ui-side-by-side-diff-screen-reviewed.png
Binary files differ
diff --git a/Documentation/index.txt b/Documentation/index.txt
index e56e7ca..dc94b14 100644
--- a/Documentation/index.txt
+++ b/Documentation/index.txt
@@ -75,6 +75,7 @@
 . link:config-reverseproxy.html[Reverse Proxy]
 . link:config-auto-site-initialization.html[Automatic Site Initialization on Startup]
 . link:pgm-index.html[Server Side Administrative Tools]
+. link:repository-maintenance.html[Repository Maintenance]
 . link:user-request-tracing.html[Request Tracing]
 . link:note-db.html[NoteDb]
 . link:config-accounts.html[Accounts on NoteDb]
diff --git a/Documentation/repository-maintenance.txt b/Documentation/repository-maintenance.txt
new file mode 100644
index 0000000..1672436
--- /dev/null
+++ b/Documentation/repository-maintenance.txt
@@ -0,0 +1,116 @@
+= Gerrit Code Review - Repository Maintenance
+
+== Description
+
+Each project in Gerrit is stored in a bare Git repository. Gerrit uses
+the JGit library to access (read and write to) these Git repositories.
+As modifications are made to a project, Git repository maintenance will
+be needed or performance will eventually suffer. When using the Git
+command line tool to operate on a Git repository, it will run `git gc`
+every now and then on the repository to ensure that Git garbage
+collection is performed. However regular maintenance does not happen as
+a result of normal Gerrit operations, so this is something that Gerrit
+administrators need to plan for.
+
+Gerrit has a built-in feature which allows it to run Git garbage
+collection on repositories. This can be
+link:config-gerrit.html#gc[configured] to run on a regular basis, and/or
+this can be run manually with the link:cmd-gc.html[gerrit gc] ssh
+command, or with the link:rest-api-projects.html#run-gc[run-gc] REST API.
+Some administrators will opt to run `git gc` or `jgit gc` outside of
+Gerrit instead. There are many reasons this might be done, the main one
+likely being that when it is run in Gerrit it can be very resource
+intensive and scheduling an external job to run Git garbage collection
+allows administrators to finely tune the approach and resource usage of
+this maintenance.
+
+== Git Garbage Collection Impacts
+
+Unlike a typical server database, access to Git repositories is not
+marshalled through a single process or a set of inter communicating
+processes. Unfortuntatlely the design of the on-disk layout of a Git
+repository does not allow for 100% race free operations when accessed by
+multiple actors concurrently. These design shortcomings are more likely
+to impact the operations of busy repositories since racy conditions are
+more likely to occur when there are more concurrent operations. Since
+most Gerrit servers are expected to run without interruptions, Git
+garbage collection likely needs to be run during normal operational hours.
+When it runs, it adds to the concurrency of the overall accesses. Given
+that many of the operations in garbage collection involve deleting files
+and directories, it has a higher chance of impacting other ongoing
+operations than most other operations.
+
+=== Interrupted Operations
+
+When Git garbage collection deletes a file or directory that is
+currently in use by an ongoing operation, it can cause that operation to
+fail. These sorts of failures are often single shot failures, i.e. the
+operation will succeed if tried again. An example of such a failure is
+when a pack file is deleted while Gerrit is sending an object in the
+file over the network to a user performing a clone or fetch. Usually
+pack files are only deleted when the referenced objects in them have
+been repacked and thus copied to a new pack file. So performing the same
+operation again after the fetch will likely send the same object from
+the new pack instead of the deleted one, and the operation will succeed.
+
+=== Data Loss
+
+It is possible for data loss to occur when Git garbage collection runs.
+This is very rare, but it can happen. This can happen when an object is
+believed to be unreferenced when object repacking is running, and then
+garbage collection deletes it. This can happen because even though an
+object may indeed be unreferenced when object repacking begins and
+reachability of all objects is determined, it can become referenced by
+another concurrent operation after this unreferenced determination but
+before it gets deleted. When this happens, a new reference can be
+created which points to a now missing object, and this will result in a
+loss.
+
+== Reducing Git Garbage Collection Impacts
+
+JGit has a `preserved` directory feature which is intended to reduce
+some of the impacts of Git garbage collection, and Gerrit can take
+advantage of the feature too. The `preserved` directory is a
+subdirectory of a repository's `objects/pack` directory where JGit will
+move pack files that it would normally delete when `jgit gc` is invoked
+with the `--preserve-oldpacks` option. It will later delete these files
+the next time that `jgit gc` is run if it is invoked with the
+`--prune-preserved` option. Using these flags together on every `jgit gc`
+invocation means that packfiles will get an extended lifetime by one
+full garbage collection cycle. Since an atomic move is used to move these
+files, any open references to them will continue to work, even on NFS. On
+a busy repository, preserving pack files can make operations much more
+reliable, and interrupted operations should almost entirely disappear.
+
+Moving files to the `preserved` directory also has the ability to reduce
+data loss. If JGit cannot find an object it needs in its current object
+DB, it will look into the `preserved` directory as a last resort. If it
+finds the object in a pack file there, it will restore the
+slated-to-be-deleted pack file back to the original `objects/pack`
+directory effectively "undeleting" it and making all the objects in it
+available again. When this happens, data loss is prevented.
+
+One advantage of restoring preserved packfiles in this way when an
+object is referenced in them, is that it makes loosening unreferenced
+objects during Git garbage collection, which is a potentially expensive,
+wasteful, and performance impacting operation, no longer desirable. It
+is recommended that if you use Git for garbage collection, that you use
+the `-a` option to `git repack` instead of the `-A` option to no longer
+perform this loosening.
+
+When Git is used for garbage collection instead of JGit, it is fairly
+easy to wrap `git gc` or `git repack` with a small script which has a
+`--prune-preserved` option which behaves as mentioned above by deleting
+any pack files currently in the preserved directory, and also has a
+`--preserve-oldpacks` option which then hardlinks all the currently
+existing pack files from the `objects/pack` directory into the
+`preserved` directory right before calling the real Git command. This
+approach will then behave similarly to `jgit gc` with respect to
+preserving pack files.
+
+GERRIT
+------
+Part of link:index.html[Gerrit Code Review]
+
+SEARCHBOX
+---------
diff --git a/Documentation/user-review-ui.txt b/Documentation/user-review-ui.txt
index 9eacaed..156ea02 100644
--- a/Documentation/user-review-ui.txt
+++ b/Documentation/user-review-ui.txt
@@ -93,13 +93,6 @@
 
 image::images/gwt-user-review-ui-change-screen-change-info.png[width=800, link="images/gwt-user-review-ui-change-screen-change-info.png"]
 
-- [[change-owner]]Change Owner:
-+
-The owner of the change is displayed as a link to a list of the owner's
-changes that have the same status as the currently viewed change.
-+
-image::images/gwt-user-review-ui-change-screen-change-info-owner.png[width=800, link="images/gwt-user-review-ui-change-screen-change-info-owner.png"]
-
 - [[reviewers]]Reviewers:
 +
 The reviewers of the change are displayed as chip tokens.
@@ -163,10 +156,6 @@
 +
 image::images/gwt-user-review-ui-change-screen-change-info-cannot-merge.png[width=800, link="images/gwt-user-review-ui-change-screen-change-info-cannot-merge.png"]
 
-- [[update-time]]Time of Last Update:
-+
-image::images/gwt-user-review-ui-change-screen-change-info-last-update.png[width=800, link="images/gwt-user-review-ui-change-screen-change-info-last-update.png"]
-
 - [[actions]]Actions:
 +
 Depending on the change state and the permissions of the user, different
@@ -658,7 +647,7 @@
 comments; a summary comment is only added if the reply popup panel is
 open when the quick approve button is clicked.
 
-image::images/gwt-user-review-ui-change-screen-quick-approve.png[width=800, link="images/gwt-user-review-ui-change-screen-quick-approve.png"]
+image::images/user-review-ui-change-screen-quick-approve.png[width=800, link="images/gwt-user-review-ui-change-screen-quick-approve.png"]
 
 [[history]]
 === History
@@ -739,28 +728,12 @@
 image::images/gwt-user-review-ui-side-by-side-diff-screen-project-and-file.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-project-and-file.png"]
 
 [[side-by-side-mark-reviewed]]
-The checkbox in front of the project name and the file name allows the
+The checkbox in front of the file name allows the
 patch to be marked as reviewed. The link:#mark-reviewed[Mark Reviewed]
 diff preference allows to control whether the files should be
 automatically marked as reviewed when they are viewed.
 
-image::images/gwt-user-review-ui-side-by-side-diff-screen-reviewed.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-reviewed.png"]
-
-[[scrollbar]]
-The scrollbar shows patch diffs and inline comments as annotations.
-This provides a good overview of the lines in the patch that are
-relevant for reviewing. By clicking on an annotation one can quickly
-navigate to the corresponding line in the patch.
-
-image::images/gwt-user-review-ui-side-by-side-diff-screen-scrollbar.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-scrollbar.png"]
-
-[[gaps]]
-A gap between lines in the file content that is caused by aligning the
-left and right side or by displaying inline comments is shown as a
-vertical red bar in the line number column. This prevents a gap from
-being mistaken for blank lines in the file
-
-image::images/gwt-user-review-ui-side-by-side-diff-screen-red-bar.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-red-bar.png"]
+image::images/user-review-ui-side-by-side-diff-screen-reviewed.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-reviewed.png"]
 
 [[patch-set-selection]]
 In the header, on each side, the list of patch sets is shown. Clicking
@@ -919,52 +892,10 @@
 [[file-level-comments]]
 === File Level Comments
 
-Comments that apply to a whole file can be added on file level.
+File level comments are added by clicking the 'File' header at the top
+of the file.
 
-File level comments are added by clicking on the comment icon in the
-header above the file.
-
-image::images/gwt-user-review-ui-side-by-side-diff-screen-file-level-comment.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-file-level-comment.png"]
-
-Clicking on the comment icon opens a comment box for typing the file
-level comment.
-
-image::images/gwt-user-review-ui-side-by-side-diff-screen-file-level-commented.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-file-level-commented.png"]
-
-[[search]]
-=== Search
-
-For searching within a patch file, a Vim-like search is supported.
-Typing `/` opens the search box. Typing in the search box immediately
-highlights matches in the patch file with a yellow background. Using
-JavaScript regular expressions in the search term is supported. The
-search is case insensitive. After confirming the search by `ENTER` one
-can navigate between the matches by `n` / `N` to go to the next /
-previous match. Skipped lines are automatically expanded if they
-contain a match and one navigates to it.
-
-For additional possibilities to search please check the
-link:http://www.vim.org/docs.php[Vim documentation,role=external,window=_blank]. There are other
-useful ways to search, e.g. while the cursor is on a word, pressing `*`
-or `#` searches for the next or previous occurrence of the word.
-
-Searching by `Ctrl-F` finds matches only in the visible area of the
-screen unless the link:#render[Render] diff preference is set to `Slow`.
-
-image::images/gwt-user-review-ui-side-by-side-diff-screen-search.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-search.png"]
-
-[[key-navigation]]
-=== Key Navigation
-
-Vim-like commands can be used to navigate within a patch file:
-
-- `h` / `j` / `k` / `l` moves the cursor left / down / up / right
-- `0` / `$` moves the cursor to the start / end of the line
-- `gg` / `G` moves to cursor to the start / end of the file
-- `Ctrl-D` / `Ctrl-U` scrolls downwards / upwards
-
-Please check the link:http://www.vim.org/docs.php[Vim documentation,role=external,window=_blank]
-for further information.
+image::images/user-review-ui-side-by-side-diff-screen-file-level-comment.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-file-level-comment.png"]
 
 [[diff-preferences]]
 === Diff Preferences
@@ -974,27 +905,10 @@
 preferences. The diff preferences can be accessed by clicking on the
 settings icon in the screen header.
 
-image::images/gwt-user-review-ui-side-by-side-diff-screen-preferences.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-preferences.png"]
-
-The diff preferences popup allows to change the diff preferences.
-By clicking on the `Save` button changes to the diff preferences are
-saved permanently. Clicking on the `Apply` button applies the new
-diff preferences to the current screen, but they are discarded when the
-screen is refreshed. The `Save` button is only available if the user is
-signed in.
-
-image::images/gwt-user-review-ui-side-by-side-diff-screen-preferences-popup.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-preferences-popup.png"]
+image::images/user-review-ui-side-by-side-diff-screen-preferences.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-preferences.png"]
 
 The following diff preferences can be configured:
 
-- [[theme]]`Theme`:
-+
-Controls the theme that is used to render the file content.
-+
-E.g. users could choose to work with a dark theme.
-+
-image::images/gwt-user-review-ui-side-by-side-diff-screen-dark-theme.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-dark-theme.png"]
-
 - [[ignore-whitespace]]`Ignore Whitespace`:
 +
 Controls whether differences in whitespace should be ignored or not.
@@ -1003,11 +917,11 @@
 +
 All differences in whitespace are highlighted.
 +
-** `At Line End`:
+** `Trailing`:
 +
 Whitespace differences at the end of lines are ignored.
 +
-** `Leading, At Line End`:
+** `Leading, Trailing`:
 +
 Whitespace differences at the beginning and end of lines are ignored.
 +
@@ -1021,11 +935,7 @@
 
 - [[columns]]`Columns`:
 +
-Sets the preferred line length. At this position a vertical dashed line
-is displayed so that one can easily detect lines the exceed the
-preferred line length.
-+
-image::images/gwt-user-review-ui-side-by-side-diff-screen-column.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-column.png"]
+Sets the preferred line length. At this position, lines are wrapped.
 
 - [[lines-of-context]]`Lines Of Context`:
 +
@@ -1042,84 +952,28 @@
 If many lines are skipped there are additional links to expand the
 context by ten lines before and after the skipped block.
 +
-image::images/gwt-user-review-ui-side-by-side-diff-screen-expand-skipped-lines.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-expand-skipped-lines.png"]
+image::images/user-review-ui-side-by-side-diff-screen-expand-skipped-lines.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-expand-skipped-lines.png"]
 
 - [[syntax-highlighting]]`Syntax Highlighting`:
 +
 Controls whether syntax highlighting should be enabled.
 +
 The language for the syntax highlighting is automatically detected from
-the file extension. The language can also be set manually by selecting
-it from the `Language` drop-down list.
-+
-image::images/gwt-user-review-ui-side-by-side-diff-screen-syntax-coloring.png[width=800, link="images/gwt-user-review-ui-side-by-side-diff-screen-syntax-coloring.png"]
+the file extension.
 
-- [[whitespace-errors]]`Whitespace Errors`:
+- [[whitespace-errors]]`Show trailing whitespace`:
 +
-Controls whether whitespace errors are highlighted.
+Controls whether trailing whitespace is highlighted.
 
 - [[show-tabs]]`Show Tabs`:
 +
 Controls whether tabs are highlighted.
 
-- [[line-numbers]]`Line Numbers`:
-+
-Controls whether line numbers are shown.
-
-- [[empty-pane]]`Empty Pane`:
-+
-Controls whether empty panes are shown or not. The Left pane is empty when a
-file was added; the right pane is empty when a file was deleted.
-
-- [[left-side]]`Left Side`:
-+
-Controls whether the left side is shown. This preference is not
-persistent and is ignored by the `Save` button. Every time a
-patch diff is opened, this preference is reset to `Show`.
-
-- [[top-menu]]`Top Menu`:
-+
-Controls whether the top menu is shown.
-
-- [[auto-hide-diff-table-header]]`Auto Hide Diff Table Header`:
-+
-Controls whether the diff table header should be automatically hidden
-when scrolling down more than half of a page.
-
 - [[mark-reviewed]]`Mark Reviewed`:
 +
 Controls whether the files of the patch set should be automatically
 marked as reviewed when they are viewed.
 
-- [[expand-all-comments]]`Expand All Comments`:
-+
-Controls whether all comments should be automatically expanded.
-
-- [[render]]`Render`:
-+
-Controls how patch files that exceed the screen size are rendered.
-+
-If `Fast` is selected file contents which are outside of the visible
-area are not attached to the browser's DOM tree. This makes the
-rendering fast, but searching by `Ctrl+F` only finds content which is
-in the visible area.
-+
-If `Slow` is selected all file contents are attached to the browser's
-DOM tree, which makes the rendering slow for large files. The advantage
-of this setting is that `Ctrl+F` can be used to search in the complete
-file.
-+
-Large files that exceed 4000 lines will not be fully rendered.
-
-- [[line-wrapping]]`Line Wrapping`:
-+
-Controls whether to enable line wrapping or not.
-+
-If `false` is selected then line wrapping is disabled.
-This is the default option.
-+
-If `true` is selected then line wrapping is enabled.
-
 [[keyboard-shortcuts]]
 == Keyboard Shortcuts
 
diff --git a/java/com/google/gerrit/server/change/ActionJson.java b/java/com/google/gerrit/server/change/ActionJson.java
index 6f28dad..54ebf40 100644
--- a/java/com/google/gerrit/server/change/ActionJson.java
+++ b/java/com/google/gerrit/server/change/ActionJson.java
@@ -31,7 +31,7 @@
 import com.google.gerrit.extensions.webui.UiAction;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.extensions.webui.UiActions;
-import com.google.gerrit.server.notedb.ChangeNotes;
+import com.google.gerrit.server.query.change.ChangeData;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
@@ -89,9 +89,9 @@
     return Lists.newArrayList(visitorSet);
   }
 
-  void addChangeActions(ChangeInfo to, ChangeNotes notes) {
+  void addChangeActions(ChangeInfo to, ChangeData changeData) {
     List<ActionVisitor> visitors = visitors();
-    to.actions = toActionMap(notes, visitors, copy(visitors, to));
+    to.actions = toActionMap(changeData, visitors, copy(visitors, to));
   }
 
   void addRevisionActions(@Nullable ChangeInfo changeInfo, RevisionInfo to, RevisionResource rsrc) {
@@ -167,7 +167,7 @@
   }
 
   private Map<String, ActionInfo> toActionMap(
-      ChangeNotes notes, List<ActionVisitor> visitors, ChangeInfo changeInfo) {
+      ChangeData changeData, List<ActionVisitor> visitors, ChangeInfo changeInfo) {
     CurrentUser user = userProvider.get();
     Map<String, ActionInfo> out = new LinkedHashMap<>();
     if (!user.isIdentifiedUser()) {
@@ -175,12 +175,12 @@
     }
 
     Iterable<UiAction.Description> descs =
-        uiActions.from(changeViews, changeResourceFactory.create(notes, user));
+        uiActions.from(changeViews, changeResourceFactory.create(changeData, user));
 
     // The followup action is a client-side only operation that does not
     // have a server side handler. It must be manually registered into the
     // resulting action map.
-    if (!notes.getChange().isAbandoned()) {
+    if (!changeData.change().isAbandoned()) {
       UiAction.Description descr = new UiAction.Description();
       PrivateInternals_UiActionDescription.setId(descr, "followup");
       PrivateInternals_UiActionDescription.setMethod(descr, "POST");
diff --git a/java/com/google/gerrit/server/change/ChangeJson.java b/java/com/google/gerrit/server/change/ChangeJson.java
index 1e9bc5f3..029f231 100644
--- a/java/com/google/gerrit/server/change/ChangeJson.java
+++ b/java/com/google/gerrit/server/change/ChangeJson.java
@@ -678,7 +678,7 @@
     }
 
     if (has(CURRENT_ACTIONS) || has(CHANGE_ACTIONS)) {
-      actionJson.addChangeActions(out, cd.notes());
+      actionJson.addChangeActions(out, cd);
     }
 
     if (has(TRACKING_IDS)) {
diff --git a/java/com/google/gerrit/server/change/ChangeResource.java b/java/com/google/gerrit/server/change/ChangeResource.java
index 5a1798d..3729b59 100644
--- a/java/com/google/gerrit/server/change/ChangeResource.java
+++ b/java/com/google/gerrit/server/change/ChangeResource.java
@@ -44,9 +44,10 @@
 import com.google.gerrit.server.plugincontext.PluginSetContext;
 import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.server.project.ProjectState;
-import com.google.inject.Inject;
+import com.google.gerrit.server.query.change.ChangeData;
 import com.google.inject.TypeLiteral;
 import com.google.inject.assistedinject.Assisted;
+import com.google.inject.assistedinject.AssistedInject;
 import java.util.HashSet;
 import java.util.Optional;
 import java.util.Set;
@@ -66,6 +67,8 @@
 
   public interface Factory {
     ChangeResource create(ChangeNotes notes, CurrentUser user);
+
+    ChangeResource create(ChangeData changeData, CurrentUser user);
   }
 
   private static final String ZERO_ID_STRING = ObjectId.zeroId().name();
@@ -77,10 +80,10 @@
   private final StarredChangesUtil starredChangesUtil;
   private final ProjectCache projectCache;
   private final PluginSetContext<ChangeETagComputation> changeETagComputation;
-  private final ChangeNotes notes;
+  private final ChangeData changeData;
   private final CurrentUser user;
 
-  @Inject
+  @AssistedInject
   ChangeResource(
       AccountCache accountCache,
       ApprovalsUtil approvalUtil,
@@ -89,6 +92,7 @@
       StarredChangesUtil starredChangesUtil,
       ProjectCache projectCache,
       PluginSetContext<ChangeETagComputation> changeETagComputation,
+      ChangeData.Factory changeDataFactory,
       @Assisted ChangeNotes notes,
       @Assisted CurrentUser user) {
     this.accountCache = accountCache;
@@ -98,12 +102,34 @@
     this.starredChangesUtil = starredChangesUtil;
     this.projectCache = projectCache;
     this.changeETagComputation = changeETagComputation;
-    this.notes = notes;
+    this.changeData = changeDataFactory.create(notes);
+    this.user = user;
+  }
+
+  @AssistedInject
+  ChangeResource(
+      AccountCache accountCache,
+      ApprovalsUtil approvalUtil,
+      PatchSetUtil patchSetUtil,
+      PermissionBackend permissionBackend,
+      StarredChangesUtil starredChangesUtil,
+      ProjectCache projectCache,
+      PluginSetContext<ChangeETagComputation> changeETagComputation,
+      @Assisted ChangeData changeData,
+      @Assisted CurrentUser user) {
+    this.accountCache = accountCache;
+    this.approvalUtil = approvalUtil;
+    this.patchSetUtil = patchSetUtil;
+    this.permissionBackend = permissionBackend;
+    this.starredChangesUtil = starredChangesUtil;
+    this.projectCache = projectCache;
+    this.changeETagComputation = changeETagComputation;
+    this.changeData = changeData;
     this.user = user;
   }
 
   public PermissionBackend.ForChange permissions() {
-    return permissionBackend.user(user).change(notes);
+    return permissionBackend.user(user).change(getNotes());
   }
 
   public CurrentUser getUser() {
@@ -111,7 +137,7 @@
   }
 
   public Change.Id getId() {
-    return notes.getChangeId();
+    return changeData.getId();
   }
 
   /** @return true if {@link #getUser()} is the change's owner. */
@@ -121,7 +147,7 @@
   }
 
   public Change getChange() {
-    return notes.getChange();
+    return changeData.change();
   }
 
   public Project.NameKey getProject() {
@@ -129,7 +155,11 @@
   }
 
   public ChangeNotes getNotes() {
-    return notes;
+    return changeData.notes();
+  }
+
+  public ChangeData getChangeData() {
+    return changeData;
   }
 
   // This includes all information relevant for ETag computation
@@ -153,7 +183,7 @@
       accounts.add(getChange().getAssignee());
     }
     try {
-      patchSetUtil.byChange(notes).stream().map(PatchSet::uploader).forEach(accounts::add);
+      patchSetUtil.byChange(getNotes()).stream().map(PatchSet::uploader).forEach(accounts::add);
 
       // It's intentional to include the states for *all* reviewers into the ETag computation.
       // We need the states of all current reviewers and CCs because they are part of ChangeInfo.
@@ -162,7 +192,7 @@
       // set of accounts that posted a message is too expensive. However everyone who posts a
       // message is automatically added as reviewer. Hence if we include removed reviewers we can
       // be sure that we have all accounts that posted messages on the change.
-      accounts.addAll(approvalUtil.getReviewers(notes).all());
+      accounts.addAll(approvalUtil.getReviewers(getNotes()).all());
     } catch (StorageException e) {
       // This ETag will be invalidated if it loads next time.
     }
@@ -178,7 +208,7 @@
 
     ObjectId noteId;
     try {
-      noteId = notes.loadRevision();
+      noteId = getNotes().loadRevision();
     } catch (StorageException e) {
       noteId = null; // This ETag will be invalidated if it loads next time.
     }
@@ -194,7 +224,7 @@
 
     changeETagComputation.runEach(
         c -> {
-          String pluginETag = c.getETag(notes.getProjectName(), notes.getChangeId());
+          String pluginETag = c.getETag(changeData.project(), changeData.getId());
           if (pluginETag != null) {
             h.putString(pluginETag, UTF_8);
           }
@@ -207,8 +237,8 @@
         TraceContext.newTimer(
             "Compute change ETag",
             Metadata.builder()
-                .changeId(notes.getChangeId().get())
-                .projectName(notes.getProjectName().get())
+                .changeId(changeData.getId().get())
+                .projectName(changeData.project().get())
                 .build())) {
       Hasher h = Hashing.murmur3_128().newHasher();
       if (user.isIdentifiedUser()) {
diff --git a/java/com/google/gerrit/server/change/RevisionJson.java b/java/com/google/gerrit/server/change/RevisionJson.java
index 558bdba..b702440 100644
--- a/java/com/google/gerrit/server/change/RevisionJson.java
+++ b/java/com/google/gerrit/server/change/RevisionJson.java
@@ -327,7 +327,7 @@
       actionJson.addRevisionActions(
           changeInfo,
           out,
-          new RevisionResource(changeResourceFactory.create(cd.notes(), userProvider.get()), in));
+          new RevisionResource(changeResourceFactory.create(cd, userProvider.get()), in));
     }
 
     if (gpgApi.isEnabled() && has(PUSH_CERTIFICATES)) {
diff --git a/java/com/google/gerrit/server/patch/FilePathAdapter.java b/java/com/google/gerrit/server/patch/FilePathAdapter.java
index 7f34cf1..ccd1466 100644
--- a/java/com/google/gerrit/server/patch/FilePathAdapter.java
+++ b/java/com/google/gerrit/server/patch/FilePathAdapter.java
@@ -1,3 +1,17 @@
+// 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.
+
 package com.google.gerrit.server.patch;
 
 import com.google.gerrit.entities.Patch.ChangeType;
diff --git a/java/com/google/gerrit/server/restapi/change/Submit.java b/java/com/google/gerrit/server/restapi/change/Submit.java
index 790b2db..ba0720a 100644
--- a/java/com/google/gerrit/server/restapi/change/Submit.java
+++ b/java/com/google/gerrit/server/restapi/change/Submit.java
@@ -112,7 +112,6 @@
 
   private final GitRepositoryManager repoManager;
   private final PermissionBackend permissionBackend;
-  private final ChangeData.Factory changeDataFactory;
   private final Provider<MergeOp> mergeOpProvider;
   private final Provider<MergeSuperSet> mergeSuperSet;
   private final AccountResolver accountResolver;
@@ -131,7 +130,6 @@
   Submit(
       GitRepositoryManager repoManager,
       PermissionBackend permissionBackend,
-      ChangeData.Factory changeDataFactory,
       Provider<MergeOp> mergeOpProvider,
       Provider<MergeSuperSet> mergeSuperSet,
       AccountResolver accountResolver,
@@ -141,7 +139,6 @@
       ProjectCache projectCache) {
     this.repoManager = repoManager;
     this.permissionBackend = permissionBackend;
-    this.changeDataFactory = changeDataFactory;
     this.mergeOpProvider = mergeOpProvider;
     this.mergeSuperSet = mergeSuperSet;
     this.accountResolver = accountResolver;
@@ -311,7 +308,7 @@
       throw new StorageException("Could not determine problems for the change", e);
     }
 
-    ChangeData cd = changeDataFactory.create(resource.getNotes());
+    ChangeData cd = resource.getChangeResource().getChangeData();
     try {
       MergeOp.checkSubmitRule(cd, false);
     } catch (ResourceConflictException e) {
diff --git a/javatests/com/google/gerrit/acceptance/api/change/ChangeSubmitRequirementIT.java b/javatests/com/google/gerrit/acceptance/api/change/ChangeSubmitRequirementIT.java
index 9cb9058..c6b57da 100644
--- a/javatests/com/google/gerrit/acceptance/api/change/ChangeSubmitRequirementIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/change/ChangeSubmitRequirementIT.java
@@ -24,6 +24,7 @@
 import com.google.gerrit.extensions.annotations.Exports;
 import com.google.gerrit.extensions.api.changes.ChangeApi;
 import com.google.gerrit.extensions.api.changes.ReviewInput;
+import com.google.gerrit.extensions.client.ListChangesOption;
 import com.google.gerrit.extensions.common.ChangeInfo;
 import com.google.gerrit.extensions.common.LegacySubmitRequirementInfo;
 import com.google.gerrit.extensions.config.FactoryModule;
@@ -35,6 +36,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
+import java.util.concurrent.atomic.AtomicInteger;
 import org.junit.Test;
 
 public class ChangeSubmitRequirementIT extends AbstractDaemonTest {
@@ -58,7 +60,7 @@
     };
   }
 
-  @Inject CustomSubmitRule rule;
+  @Inject private CustomSubmitRule rule;
 
   @Test
   public void submitRequirementIsPropagated() throws Exception {
@@ -170,6 +172,35 @@
     assertThat(result.get(0).changeId).isEqualTo(change.info().changeId);
   }
 
+  @Test
+  public void submitRuleIsInvokedOnlyOnceWhenGettingChangeDetails() throws Exception {
+    PushOneCommit.Result r = createChange("Some Change", "foo.txt", "some content");
+    String changeId = r.getChangeId();
+
+    rule.numberOfEvaluations.set(0);
+    gApi.changes()
+        .id(changeId)
+        .get(ListChangesOption.ALL_REVISIONS, ListChangesOption.CURRENT_ACTIONS);
+
+    // Submit rules are computed freshly, but only once.
+    assertThat(rule.numberOfEvaluations.get()).isEqualTo(1);
+  }
+
+  @Test
+  public void submitRuleIsNotInvokedWhenQueryingChange() throws Exception {
+    PushOneCommit.Result r = createChange("Some Change", "foo.txt", "some content");
+    String changeId = r.getChangeId();
+
+    rule.numberOfEvaluations.set(0);
+    gApi.changes()
+        .query(changeId)
+        .withOptions(ListChangesOption.ALL_REVISIONS, ListChangesOption.CURRENT_ACTIONS)
+        .get();
+
+    // Submit rule evaluation results from the change index are reused
+    assertThat(rule.numberOfEvaluations.get()).isEqualTo(0);
+  }
+
   private List<ChangeInfo> queryIsSubmittable() throws Exception {
     return gApi.changes().query("is:submittable project:" + project.get()).get();
   }
@@ -189,6 +220,7 @@
   @Singleton
   private static class CustomSubmitRule implements SubmitRule {
     private Optional<SubmitRecord.Status> recordStatus = Optional.empty();
+    private AtomicInteger numberOfEvaluations = new AtomicInteger();
 
     public void block(boolean block) {
       this.status(block ? Optional.of(SubmitRecord.Status.NOT_READY) : Optional.empty());
@@ -200,6 +232,7 @@
 
     @Override
     public Optional<SubmitRecord> evaluate(ChangeData changeData) {
+      numberOfEvaluations.incrementAndGet();
       if (this.recordStatus.isPresent()) {
         SubmitRecord record = new SubmitRecord();
         record.labels = new ArrayList<>();
diff --git a/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata_html.ts b/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata_html.ts
index 8c8a886..ed38d6f 100644
--- a/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata_html.ts
+++ b/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata_html.ts
@@ -153,7 +153,14 @@
     <section
       class$="[[_computeDisplayState(_showAllSections, change, _SECTION.UPDATED)]]"
     >
-      <span class="title">Updated</span>
+      <span class="title">
+        <gr-tooltip-content
+          has-tooltip=""
+          title="Last update of (meta)data for this change."
+        >
+          Updated
+        </gr-tooltip-content>
+      </span>
       <span class="value">
         <gr-date-formatter
           has-tooltip=""
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder.ts b/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder.ts
index 874f572..eb943f7 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder.ts
@@ -345,7 +345,8 @@
         contextGroups,
         showAbove,
         showBelow,
-        numLines
+        numLines,
+        viewMode
       )
     );
     if (showBelow) {
@@ -364,19 +365,36 @@
     contextGroups: GrDiffGroup[],
     showAbove: boolean,
     showBelow: boolean,
-    numLines: number
+    numLines: number,
+    viewMode: DiffViewMode
   ): HTMLElement {
-    const row = this._createElement('tr', 'contextDivider');
-    if (!(showAbove && showBelow)) {
-      row.classList.add('collapsed');
+    const row = this._createElement('tr', 'dividerRow');
+    if (showAbove && !showBelow) {
+      row.classList.add('showAboveOnly');
+    } else if (!showAbove && showBelow) {
+      row.classList.add('showBelowOnly');
+    } else {
+      // Note that !showAbove && !showBelow also intentionally creates
+      // "showBoth". This means the file is completely collapsed, which is
+      // unusual, but at least happens in one test.
+      row.classList.add('showBoth');
     }
 
-    const element = this._createElement('td', 'dividerCell');
-    row.appendChild(element);
+    row.appendChild(this._createBlameCell(0));
+    if (viewMode === DiffViewMode.SIDE_BY_SIDE) {
+      row.appendChild(this._createElement('td'));
+    }
+
+    const cell = this._createElement('td', 'dividerCell');
+    cell.setAttribute('colspan', '3');
+    row.appendChild(cell);
+    const verticalFlex = this._createElement('div', 'verticalFlex');
+    cell.appendChild(verticalFlex);
+    const horizontalFlex = this._createElement('div', 'horizontalFlex');
+    verticalFlex.appendChild(horizontalFlex);
 
     const showAllContainer = this._createElement('div', 'aboveBelowButtons');
-    element.appendChild(showAllContainer);
-
+    horizontalFlex.appendChild(showAllContainer);
     const showAllButton = this._createContextButton(
       ContextButtonType.ALL,
       section,
@@ -415,7 +433,7 @@
           )
         );
       }
-      element.appendChild(container);
+      horizontalFlex.appendChild(container);
     }
 
     return row;
diff --git a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff_html.ts b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff_html.ts
index a93d5b5..e254728 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff_html.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff_html.ts
@@ -318,38 +318,64 @@
       height: calc(var(--line-height-normal) + var(--spacing-s));
     }
 
-    .contextDivider {
-      height: var(--divider-height);
-      /* Create a positioning context. */
-      transform: translateX(0px);
+    .dividerCell {
+      vertical-align: top;
     }
-    .contextDivider.collapsed {
-      /* Hide divider gap, but still show child elements (expansion buttons). */
+    .dividerRow.showBoth .dividerCell {
+      height: var(--divider-height);
+    }
+    .dividerRow.showAboveOnly .dividerCell,
+    .dividerRow.showBelowOnly .dividerCell {
       height: 0;
     }
-    .dividerCell {
-      width: 100%;
-      height: 100%;
+
+    .verticalFlex {
+      display: flex;
+      flex-direction: column;
+      position: relative;
+    }
+    .dividerRow.showBoth .verticalFlex {
+      justify-content: center;
+      margin-top: calc(0px - var(--line-height-normal) - var(--spacing-s));
+      margin-bottom: calc(0px - var(--line-height-normal) - var(--spacing-s));
+      height: calc(
+        2 * var(--line-height-normal) + 2 * var(--spacing-s) +
+          var(--divider-height) - 1px
+      );
+    }
+    .dividerRow.showAboveOnly .verticalFlex {
+      justify-content: flex-end;
+      /* margin-top has to make room for height+1px. */
+      margin-top: calc(-1px - var(--line-height-normal) - var(--spacing-s));
+      height: calc(var(--line-height-normal) + var(--spacing-s));
+    }
+    .dividerRow.showBelowOnly .verticalFlex {
+      justify-content: flex-start;
+      /* This just pushes the container down 1 pixel as to render below the
+         1px border-top of the padding row below. The same could be achieved
+         by position:relative; top:1px.*/
+      margin-top: 1px;
+      margin-bottom: calc(0px - var(--line-height-normal) - var(--spacing-s));
+    }
+
+    .horizontalFlex {
       display: flex;
       justify-content: center;
-      position: absolute;
-      top: 0;
-      left: 0;
+    }
+    .dividerRow.showBoth .horizontalFlex {
+      align-items: center;
+    }
+    .dividerRow.showAboveOnly .horizontalFlex {
+      align-items: end;
+    }
+    .dividerRow.showBelowOnly .horizontalFlex {
+      align-items: start;
     }
     .contextControlButton {
       background-color: var(--default-button-background-color);
       font: var(--context-control-button-font, inherit);
-      /* All position is relative to container, so ignore sibling buttons. */
-      position: absolute;
-    }
-    .contextControlButton:first-child {
-      /* First button needs to claim width to display without text wrapping. */
-      position: relative;
     }
     .centeredButton {
-      /* Center over divider. */
-      top: 50%;
-      transform: translateY(-50%);
       --gr-button: {
         color: var(--diff-context-control-color);
         border-style: solid;
@@ -368,15 +394,17 @@
     .aboveBelowButtons {
       display: flex;
       flex-direction: column;
+      justify-content: center;
       margin-left: var(--spacing-m);
-      position: relative;
     }
     .aboveBelowButtons:first-child {
       margin-left: 0;
     }
+    .dividerRow.showBoth .aboveButton {
+      /* The size of the gap between the above and below button. */
+      margin-bottom: calc(var(--divider-height) + 1px);
+    }
     .aboveButton {
-      /* Display over preceding content / background placeholder. */
-      transform: translateY(-100%);
       --gr-button: {
         color: var(--diff-context-control-color);
         border-style: solid;
@@ -393,8 +421,6 @@
       }
     }
     .belowButton {
-      /* Display over following content / background placeholder. */
-      top: calc(100% + var(--divider-border));
       --gr-button: {
         color: var(--diff-context-control-color);
         border-style: solid;
diff --git a/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog.ts b/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog.ts
index 39a5d54..3763fbf 100644
--- a/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog.ts
+++ b/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog.ts
@@ -30,7 +30,6 @@
   $: {
     name: HTMLInputElement;
     username: HTMLInputElement;
-    email: HTMLSelectElement;
   };
 }
 
@@ -73,11 +72,17 @@
   _serverConfig?: ServerInfo;
 
   @property({
-    computed: '_computeUsernameMutable(_serverConfig,_account.username)',
+    computed: '_computeUsernameMutable(_account.username)',
     type: Boolean,
   })
   _usernameMutable = false;
 
+  @property({type: Boolean})
+  _hasUsernameChange?: boolean;
+
+  @property({type: String, observer: '_usernameChanged'})
+  _username?: string;
+
   private readonly restApiService = appContext.restApiService;
 
   /** @override */
@@ -86,26 +91,17 @@
     this._ensureAttribute('role', 'dialog');
   }
 
-  _computeUsernameMutable(config?: ServerInfo, username?: string) {
-    // Polymer 2: check for undefined
-    // username is not being checked for undefined as we want to avoid
-    // setting it null explicitly to trigger the computation
-    if (config === undefined) {
-      return false;
-    }
-
-    return (
-      config.auth.editable_account_fields.includes(
-        EditableAccountField.USER_NAME
-      ) && !username
-    );
-  }
-
   loadData() {
     this._loading = true;
 
     const loadAccount = this.restApiService.getAccount().then(account => {
-      this._account = {...this._account, ...account};
+      if (!account) return;
+      this._hasUsernameChange = false;
+      // Provide predefined value for username to trigger computation of
+      // username mutability.
+      account.username = account.username || '';
+      this._account = account;
+      this._username = account.username;
     });
 
     const loadConfig = this.restApiService.getConfig().then(config => {
@@ -117,17 +113,34 @@
     });
   }
 
+  _usernameChanged() {
+    if (this._loading || !this._account) {
+      return;
+    }
+    this._hasUsernameChange =
+      (this._account.username || '') !== (this._username || '');
+  }
+
+  _computeUsernameMutable(username?: string) {
+    // Username may not be changed once it is set.
+    return !username;
+  }
+
+  _computeUsernameEditable(config?: ServerInfo) {
+    return !!config?.auth.editable_account_fields.includes(
+      EditableAccountField.USER_NAME
+    );
+  }
+
   _save() {
     this._saving = true;
-    const promises = [
-      this.restApiService.setAccountName(this.$.name.value),
-      this.restApiService.setPreferredAccountEmail(this.$.email.value || ''),
-    ];
 
-    if (this._usernameMutable) {
-      promises.push(
-        this.restApiService.setAccountUsername(this.$.username.value)
-      );
+    const promises = [this.restApiService.setAccountName(this.$.name.value)];
+
+    // Note that we are intentionally not acting on this._username being the
+    // empty string (which is falsy).
+    if (this._hasUsernameChange && this._usernameMutable && this._username) {
+      promises.push(this.restApiService.setAccountUsername(this._username));
     }
 
     return Promise.all(promises).then(() => {
@@ -151,12 +164,8 @@
     fireEvent(this, 'close');
   }
 
-  _computeSaveDisabled(name?: string, email?: string, saving?: boolean) {
-    return !name || !email || saving;
-  }
-
-  _computeUsernameClass(usernameMutable: boolean) {
-    return usernameMutable ? '' : 'hide';
+  _computeSaveDisabled(name?: string, username?: string, saving?: boolean) {
+    return saving || (!name && !username);
   }
 
   @observe('_loading')
diff --git a/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog_html.ts b/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog_html.ts
index a1d6a5c..4b86709 100644
--- a/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog_html.ts
+++ b/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog_html.ts
@@ -59,9 +59,6 @@
     input {
       width: 20em;
     }
-    section.hide {
-      display: none;
-    }
   </style>
   <div class="container gr-form-styles">
     <header>Please confirm your contact information</header>
@@ -75,36 +72,36 @@
       </p>
       <hr />
       <section>
-        <div class="title">Full Name</div>
-        <iron-input bind-value="{{_account.name}}">
-          <input
-            is="iron-input"
-            id="name"
-            bind-value="{{_account.name}}"
-            disabled="[[_saving]]"
-          />
-        </iron-input>
+        <span class="title">Full Name</span>
+        <span class="value">
+          <iron-input bind-value="{{_account.name}}">
+            <input
+              is="iron-input"
+              id="name"
+              bind-value="{{_account.name}}"
+              disabled="[[_saving]]"
+            />
+          </iron-input>
+        </span>
       </section>
-      <section class$="[[_computeUsernameClass(_usernameMutable)]]">
-        <div class="title">Username</div>
-        <iron-input bind-value="{{_account.username}}">
-          <input
-            is="iron-input"
-            id="username"
-            bind-value="{{_account.username}}"
-            disabled="[[_saving]]"
-          />
-        </iron-input>
-      </section>
-      <section>
-        <div class="title">Preferred Email</div>
-        <select id="email" disabled="[[_saving]]">
-          <option value="[[_account.email]]">[[_account.email]]</option>
-          <template is="dom-repeat" items="[[_account.secondary_emails]]">
-            <option value="[[item]]">[[item]]</option>
-          </template>
-        </select>
-      </section>
+      <template is="dom-if" if="[[_computeUsernameEditable(_serverConfig)]]">
+        <section>
+          <span class="title">Username</span>
+          <span hidden$="[[_usernameMutable]]" class="value"
+            >[[_username]]</span
+          >
+          <span hidden$="[[!_usernameMutable]]" class="value">
+            <iron-input bind-value="{{_username}}">
+              <input
+                is="iron-input"
+                id="username"
+                bind-value="{{_username}}"
+                disabled="[[_saving]]"
+              />
+            </iron-input>
+          </span>
+        </section>
+      </template>
       <hr />
       <p>
         More configuration options for Gerrit may be found in the
@@ -123,7 +120,7 @@
         id="saveButton"
         primary=""
         link=""
-        disabled="[[_computeSaveDisabled(_account.name, _account.email, _saving)]]"
+        disabled="[[_computeSaveDisabled(_account.name, _username, _saving)]]"
         on-click="_handleSave"
         >Save</gr-button
       >
diff --git a/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog_test.ts b/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog_test.ts
index ccb7404..6c21e58 100644
--- a/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-registration-dialog/gr-registration-dialog_test.ts
@@ -17,11 +17,7 @@
 import '../../../test/common-test-setup-karma';
 import {GrRegistrationDialog} from './gr-registration-dialog';
 import {queryAndAssert, stubRestApi} from '../../../test/test-utils';
-import {
-  AccountDetailInfo,
-  EmailAddress,
-  Timestamp,
-} from '../../../types/common';
+import {AccountDetailInfo, Timestamp} from '../../../types/common';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {AuthType, EditableAccountField} from '../../../constants/constants';
 import {createServerInfo} from '../../../test/test-data-generators';
@@ -39,8 +35,6 @@
 
     account = {
       name: 'name',
-      email: 'email' as EmailAddress,
-      secondary_emails: ['email2', 'email3'],
       registered_on: '2018-02-08 18:49:18.000000000' as Timestamp,
     };
 
@@ -53,10 +47,6 @@
       account.username = username;
       return Promise.resolve();
     });
-    stubRestApi('setPreferredAccountEmail').callsFake(email => {
-      account.email = email as EmailAddress;
-      return Promise.resolve();
-    });
     stubRestApi('getConfig').returns(
       Promise.resolve({
         ...createServerInfo(),
@@ -116,93 +106,59 @@
   test('saves account details', done => {
     flush(() => {
       element.$.name.value = 'new name';
-      element.$.username.value = 'new username';
-      element.$.email.value = 'email3';
+
+      element.set('_account.username', '');
+      element._hasUsernameChange = false;
+      assert.isTrue(element._usernameMutable);
+
+      element.set('_username', 'new username');
 
       // Nothing should be committed yet.
       assert.equal(account.name, 'name');
       assert.isNotOk(account.username);
-      assert.equal(account.email, 'email' as EmailAddress);
 
       // Save and verify new values are committed.
       save()
         .then(() => {
           assert.equal(account.name, 'new name');
           assert.equal(account.username, 'new username');
-          assert.equal(account.email, 'email3' as EmailAddress);
         })
         .then(done);
     });
   });
 
-  test('email select properly populated', done => {
-    element._account = {
-      email: 'foo' as EmailAddress,
-      secondary_emails: ['bar', 'baz'],
-    };
-    flush(() => {
-      assert.equal(element.$.email.value, 'foo');
-      done();
-    });
-  });
-
   test('save btn disabled', () => {
     const compute = element._computeSaveDisabled;
     assert.isTrue(compute('', '', false));
-    assert.isTrue(compute('', 'test', false));
-    assert.isTrue(compute('test', '', false));
+    assert.isFalse(compute('', 'test', false));
+    assert.isFalse(compute('test', '', false));
     assert.isTrue(compute('test', 'test', true));
     assert.isFalse(compute('test', 'test', false));
   });
 
   test('_computeUsernameMutable', () => {
+    assert.isTrue(element._computeUsernameMutable(undefined));
+    assert.isFalse(element._computeUsernameMutable('abc'));
+  });
+
+  test('_computeUsernameEditable', () => {
     assert.isTrue(
-      element._computeUsernameMutable(
-        {
-          ...createServerInfo(),
-          auth: {
-            auth_type: AuthType.HTTP,
-            editable_account_fields: [EditableAccountField.USER_NAME],
-          },
+      element._computeUsernameEditable({
+        ...createServerInfo(),
+        auth: {
+          auth_type: AuthType.HTTP,
+          editable_account_fields: [EditableAccountField.USER_NAME],
         },
-        undefined
-      )
+      })
     );
     assert.isFalse(
-      element._computeUsernameMutable(
-        {
-          ...createServerInfo(),
-          auth: {
-            auth_type: AuthType.HTTP,
-            editable_account_fields: [EditableAccountField.USER_NAME],
-          },
+      element._computeUsernameEditable({
+        ...createServerInfo(),
+        auth: {
+          auth_type: AuthType.HTTP,
+          editable_account_fields: [],
         },
-        'abc'
-      )
-    );
-    assert.isFalse(
-      element._computeUsernameMutable(
-        {
-          ...createServerInfo(),
-          auth: {
-            auth_type: AuthType.HTTP,
-            editable_account_fields: [],
-          },
-        },
-        undefined
-      )
-    );
-    assert.isFalse(
-      element._computeUsernameMutable(
-        {
-          ...createServerInfo(),
-          auth: {
-            auth_type: AuthType.HTTP,
-            editable_account_fields: [],
-          },
-        },
-        'abc'
-      )
+      })
     );
   });
 });