Merge "Don't wrap manually in responsive modes."
diff --git a/java/com/google/gerrit/entities/LabelTypes.java b/java/com/google/gerrit/entities/LabelTypes.java
index 1c38c59..55a9976 100644
--- a/java/com/google/gerrit/entities/LabelTypes.java
+++ b/java/com/google/gerrit/entities/LabelTypes.java
@@ -20,6 +20,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 
 public class LabelTypes {
   protected List<LabelType> labelTypes;
@@ -36,12 +37,12 @@
     return labelTypes;
   }
 
-  public LabelType byLabel(LabelId labelId) {
-    return byLabel().get(labelId.get().toLowerCase());
+  public Optional<LabelType> byLabel(LabelId labelId) {
+    return Optional.ofNullable(byLabel().get(labelId.get().toLowerCase()));
   }
 
-  public LabelType byLabel(String labelName) {
-    return byLabel().get(labelName.toLowerCase());
+  public Optional<LabelType> byLabel(String labelName) {
+    return Optional.ofNullable(byLabel().get(labelName.toLowerCase()));
   }
 
   private Map<String, LabelType> byLabel() {
diff --git a/java/com/google/gerrit/entities/Project.java b/java/com/google/gerrit/entities/Project.java
index ef3cbeb..617b827 100644
--- a/java/com/google/gerrit/entities/Project.java
+++ b/java/com/google/gerrit/entities/Project.java
@@ -150,6 +150,7 @@
     return builder;
   }
 
+  @Nullable
   public String getName() {
     return getNameKey() != null ? getNameKey().get() : null;
   }
@@ -183,7 +184,7 @@
 
   @Override
   public final String toString() {
-    return Optional.of(getName()).orElse("<null>");
+    return Optional.ofNullable(getName()).orElse("<null>");
   }
 
   public abstract Builder toBuilder();
diff --git a/java/com/google/gerrit/server/PatchSetUtil.java b/java/com/google/gerrit/server/PatchSetUtil.java
index d60bc8f..326ddf4 100644
--- a/java/com/google/gerrit/server/PatchSetUtil.java
+++ b/java/com/google/gerrit/server/PatchSetUtil.java
@@ -151,8 +151,10 @@
 
     ApprovalsUtil approvalsUtil = approvalsUtilProvider.get();
     for (PatchSetApproval ap : approvalsUtil.byPatchSet(notes, change.currentPatchSetId())) {
-      LabelType type = projectState.getLabelTypes(notes).byLabel(ap.label());
-      if (type != null && ap.value() == 1 && type.getFunction() == LabelFunction.PATCH_SET_LOCK) {
+      Optional<LabelType> type = projectState.getLabelTypes(notes).byLabel(ap.label());
+      if (type.isPresent()
+          && ap.value() == 1
+          && type.get().getFunction() == LabelFunction.PATCH_SET_LOCK) {
         return true;
       }
     }
diff --git a/java/com/google/gerrit/server/approval/ApprovalInference.java b/java/com/google/gerrit/server/approval/ApprovalInference.java
index 1efbd37..8d409e5 100644
--- a/java/com/google/gerrit/server/approval/ApprovalInference.java
+++ b/java/com/google/gerrit/server/approval/ApprovalInference.java
@@ -52,6 +52,7 @@
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Map;
+import java.util.Optional;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.revwalk.RevWalk;
 
@@ -397,14 +398,14 @@
       if (resultByUser.contains(psa.label(), psa.accountId())) {
         continue;
       }
-      LabelType type = labelTypes.byLabel(psa.labelId());
+      Optional<LabelType> type = labelTypes.byLabel(psa.labelId());
       // Only compute modified files if there is a relevant label, since this is expensive.
       if (modifiedFiles == null
-          && type != null
-          && type.isCopyAllScoresIfListOfFilesDidNotChange()) {
+          && type.isPresent()
+          && type.get().isCopyAllScoresIfListOfFilesDidNotChange()) {
         modifiedFiles = listModifiedFiles(project, ps, priorPatchSet);
       }
-      if (type == null) {
+      if (!type.isPresent()) {
         logger.atFine().log(
             "approval %d on label %s of patch set %d of change %d cannot be copied"
                 + " to patch set %d because the label no longer exists on project %s",
@@ -416,8 +417,8 @@
             project.getName());
         continue;
       }
-      if (!canCopyBasedOnBooleanLabelConfigs(project, psa, ps.id(), kind, type, modifiedFiles)
-          && !canCopyBasedOnCopyCondition(notes, psa, ps.id(), type, kind)) {
+      if (!canCopyBasedOnBooleanLabelConfigs(project, psa, ps.id(), kind, type.get(), modifiedFiles)
+          && !canCopyBasedOnCopyCondition(notes, psa, ps.id(), type.get(), kind)) {
         continue;
       }
       resultByUser.put(psa.label(), psa.accountId(), psa.copyWithPatchSet(ps.id()));
diff --git a/java/com/google/gerrit/server/approval/ApprovalsUtil.java b/java/com/google/gerrit/server/approval/ApprovalsUtil.java
index b1e85e9..a1cdd99 100644
--- a/java/com/google/gerrit/server/approval/ApprovalsUtil.java
+++ b/java/com/google/gerrit/server/approval/ApprovalsUtil.java
@@ -61,6 +61,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.Set;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.revwalk.RevWalk;
@@ -299,8 +300,12 @@
     List<PatchSetApproval> cells = new ArrayList<>(approvals.size());
     Date ts = update.getWhen();
     for (Map.Entry<String, Short> vote : approvals.entrySet()) {
-      LabelType lt = labelTypes.byLabel(vote.getKey());
-      cells.add(newApproval(ps.id(), user, lt.getLabelId(), vote.getValue(), ts).build());
+      Optional<LabelType> lt = labelTypes.byLabel(vote.getKey());
+      if (!lt.isPresent()) {
+        throw new BadRequestException(
+            String.format("label \"%s\" is not a configured label", vote.getKey()));
+      }
+      cells.add(newApproval(ps.id(), user, lt.get().getLabelId(), vote.getValue(), ts).build());
     }
     for (PatchSetApproval psa : cells) {
       update.putApproval(psa.label(), psa.value());
@@ -310,11 +315,11 @@
 
   public static void checkLabel(LabelTypes labelTypes, String name, Short value)
       throws BadRequestException {
-    LabelType label = labelTypes.byLabel(name);
-    if (label == null) {
+    Optional<LabelType> label = labelTypes.byLabel(name);
+    if (!label.isPresent()) {
       throw new BadRequestException(String.format("label \"%s\" is not a configured label", name));
     }
-    if (label.getValue(value) == null) {
+    if (label.get().getValue(value) == null) {
       throw new BadRequestException(
           String.format("label \"%s\": %d is not a valid value", name, value));
     }
diff --git a/java/com/google/gerrit/server/change/FileInfoJsonExperimentImpl.java b/java/com/google/gerrit/server/change/FileInfoJsonExperimentImpl.java
index 3f7ce68..81f014d 100644
--- a/java/com/google/gerrit/server/change/FileInfoJsonExperimentImpl.java
+++ b/java/com/google/gerrit/server/change/FileInfoJsonExperimentImpl.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.server.change;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.entities.Change;
 import com.google.gerrit.entities.PatchSet;
@@ -33,7 +34,9 @@
  * FileInfoJsonNewImpl}.
  */
 public class FileInfoJsonExperimentImpl implements FileInfoJson {
-  private final String NEW_DIFF_CACHE_FEATURE = "GerritBackendRequestFeature__use_new_diff_cache";
+  @VisibleForTesting
+  public static final String NEW_DIFF_CACHE_FEATURE =
+      "GerritBackendRequestFeature__use_new_diff_cache";
 
   private final FileInfoJsonOldImpl oldImpl;
   private final FileInfoJsonNewImpl newImpl;
diff --git a/java/com/google/gerrit/server/change/LabelNormalizer.java b/java/com/google/gerrit/server/change/LabelNormalizer.java
index 30343d4..b5527d7 100644
--- a/java/com/google/gerrit/server/change/LabelNormalizer.java
+++ b/java/com/google/gerrit/server/change/LabelNormalizer.java
@@ -33,6 +33,7 @@
 import com.google.inject.Singleton;
 import java.util.Collection;
 import java.util.List;
+import java.util.Optional;
 
 /**
  * Normalizes votes on labels according to project config.
@@ -101,12 +102,12 @@
         unchanged.add(psa);
         continue;
       }
-      LabelType label = labelTypes.byLabel(psa.labelId());
-      if (label == null) {
+      Optional<LabelType> label = labelTypes.byLabel(psa.labelId());
+      if (!label.isPresent()) {
         deleted.add(psa);
         continue;
       }
-      PatchSetApproval copy = applyTypeFloor(label, psa);
+      PatchSetApproval copy = applyTypeFloor(label.get(), psa);
       if (copy.value() != psa.value()) {
         updated.add(copy);
       } else {
diff --git a/java/com/google/gerrit/server/change/LabelsJson.java b/java/com/google/gerrit/server/change/LabelsJson.java
index acff03c..5ce121b 100644
--- a/java/com/google/gerrit/server/change/LabelsJson.java
+++ b/java/com/google/gerrit/server/change/LabelsJson.java
@@ -57,6 +57,7 @@
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.TreeMap;
 
@@ -103,9 +104,9 @@
     for (SubmitRecord rec : submitRecords(cd)) {
       if (rec.labels != null) {
         for (SubmitRecord.Label r : rec.labels) {
-          LabelType type = labelTypes.byLabel(r.label);
-          if (type != null && (!isMerged || type.isAllowPostSubmit())) {
-            toCheck.put(type.getName(), type);
+          Optional<LabelType> type = labelTypes.byLabel(r.label);
+          if (type.isPresent() && (!isMerged || type.get().isAllowPostSubmit())) {
+            toCheck.put(type.get().getName(), type.get());
           }
         }
       }
@@ -120,18 +121,18 @@
         continue;
       }
       for (SubmitRecord.Label r : rec.labels) {
-        LabelType type = labelTypes.byLabel(r.label);
-        if (type == null || (isMerged && !type.isAllowPostSubmit())) {
+        Optional<LabelType> type = labelTypes.byLabel(r.label);
+        if (!type.isPresent() || (isMerged && !type.get().isAllowPostSubmit())) {
           continue;
         }
 
-        for (LabelValue v : type.getValues()) {
-          boolean ok = can.contains(new LabelPermission.WithValue(type, v));
+        for (LabelValue v : type.get().getValues()) {
+          boolean ok = can.contains(new LabelPermission.WithValue(type.get(), v));
           if (isMerged) {
             if (labels == null) {
               labels = currentLabels(filterApprovalsBy, cd);
             }
-            short prev = labels.getOrDefault(type.getName(), (short) 0);
+            short prev = labels.getOrDefault(type.get().getName(), (short) 0);
             ok &= v.getValue() >= prev;
           }
           if (ok) {
@@ -176,21 +177,21 @@
       setAllApprovals(accountLoader, cd, labels);
     }
     for (Map.Entry<String, LabelWithStatus> e : labels.entrySet()) {
-      LabelType type = labelTypes.byLabel(e.getKey());
-      if (type == null) {
+      Optional<LabelType> type = labelTypes.byLabel(e.getKey());
+      if (!type.isPresent()) {
         continue;
       }
       if (standard) {
         for (PatchSetApproval psa : cd.currentApprovals()) {
-          if (type.matches(psa)) {
+          if (type.get().matches(psa)) {
             short val = psa.value();
             Account.Id accountId = psa.accountId();
-            setLabelScores(accountLoader, type, e.getValue(), val, accountId);
+            setLabelScores(accountLoader, type.get(), e.getValue(), val, accountId);
           }
         }
       }
       if (detailed) {
-        setLabelValues(type, e.getValue());
+        setLabelValues(type.get(), e.getValue());
       }
     }
     return labels;
@@ -261,9 +262,9 @@
         MultimapBuilder.hashKeys().hashSetValues().build();
     for (PatchSetApproval a : cd.currentApprovals()) {
       allUsers.add(a.accountId());
-      LabelType type = labelTypes.byLabel(a.labelId());
-      if (type != null) {
-        labelNames.add(type.getName());
+      Optional<LabelType> type = labelTypes.byLabel(a.labelId());
+      if (type.isPresent()) {
+        labelNames.add(type.get().getName());
         // Not worth the effort to distinguish between votable/non-votable for 0
         // values on closed changes, since they can't vote anyway.
         current.put(a.accountId(), a);
@@ -292,8 +293,8 @@
 
     if (detailed) {
       labels.entrySet().stream()
-          .filter(e -> labelTypes.byLabel(e.getKey()) != null)
-          .forEach(e -> setLabelValues(labelTypes.byLabel(e.getKey()), e.getValue()));
+          .filter(e -> labelTypes.byLabel(e.getKey()).isPresent())
+          .forEach(e -> setLabelValues(labelTypes.byLabel(e.getKey()).get(), e.getValue()));
     }
 
     for (Account.Id accountId : allUsers) {
@@ -308,16 +309,16 @@
         }
       }
       for (PatchSetApproval psa : current.get(accountId)) {
-        LabelType type = labelTypes.byLabel(psa.labelId());
-        if (type == null) {
+        Optional<LabelType> type = labelTypes.byLabel(psa.labelId());
+        if (!type.isPresent()) {
           continue;
         }
 
         short val = psa.value();
-        ApprovalInfo info = byLabel.get(type.getName());
+        ApprovalInfo info = byLabel.get(type.get().getName());
         if (info != null) {
           info.value = Integer.valueOf(val);
-          info.permittedVotingRange = pvr.getOrDefault(type.getName(), null);
+          info.permittedVotingRange = pvr.getOrDefault(type.get().getName(), null);
           info.date = psa.granted();
           info.tag = psa.tag().orElse(null);
           if (psa.postSubmit()) {
@@ -328,7 +329,7 @@
           continue;
         }
 
-        setLabelScores(accountLoader, type, labels.get(type.getName()), val, accountId);
+        setLabelScores(accountLoader, type.get(), labels.get(type.get().getName()), val, accountId);
       }
     }
     return labels;
@@ -428,24 +429,24 @@
       PermissionBackend.ForChange perm = permissionBackend.absentUser(accountId).change(cd);
       Map<String, VotingRangeInfo> pvr = getPermittedVotingRanges(permittedLabels(accountId, cd));
       for (Map.Entry<String, LabelWithStatus> e : labels.entrySet()) {
-        LabelType lt = labelTypes.byLabel(e.getKey());
-        if (lt == null) {
+        Optional<LabelType> lt = labelTypes.byLabel(e.getKey());
+        if (!lt.isPresent()) {
           // Ignore submit record for undefined label; likely the submit rule
           // author didn't intend for the label to show up in the table.
           continue;
         }
         Integer value;
-        VotingRangeInfo permittedVotingRange = pvr.getOrDefault(lt.getName(), null);
+        VotingRangeInfo permittedVotingRange = pvr.getOrDefault(lt.get().getName(), null);
         String tag = null;
         Timestamp date = null;
-        PatchSetApproval psa = current.get(accountId, lt.getName());
+        PatchSetApproval psa = current.get(accountId, lt.get().getName());
         if (psa != null) {
           value = Integer.valueOf(psa.value());
           if (value == 0) {
             // This may be a dummy approval that was inserted when the reviewer
             // was added. Explicitly check whether the user can vote on this
             // label.
-            value = perm.test(new LabelPermission(lt)) ? 0 : null;
+            value = perm.test(new LabelPermission(lt.get())) ? 0 : null;
           }
           tag = psa.tag().orElse(null);
           date = psa.granted();
@@ -456,7 +457,7 @@
           // Either the user cannot vote on this label, or they were added as a
           // reviewer but have not responded yet. Explicitly check whether the
           // user can vote on this label.
-          value = perm.test(new LabelPermission(lt)) ? 0 : null;
+          value = perm.test(new LabelPermission(lt.get())) ? 0 : null;
         }
         addApproval(
             e.getValue().label(),
diff --git a/java/com/google/gerrit/server/change/ReviewerJson.java b/java/com/google/gerrit/server/change/ReviewerJson.java
index d5b74a8..6189708 100644
--- a/java/com/google/gerrit/server/change/ReviewerJson.java
+++ b/java/com/google/gerrit/server/change/ReviewerJson.java
@@ -38,6 +38,7 @@
 import com.google.inject.Singleton;
 import java.util.Collection;
 import java.util.List;
+import java.util.Optional;
 import java.util.TreeMap;
 
 @Singleton
@@ -107,10 +108,8 @@
 
     out.approvals = new TreeMap<>(labelTypes.nameComparator());
     for (PatchSetApproval ca : approvals) {
-      LabelType at = labelTypes.byLabel(ca.labelId());
-      if (at != null) {
-        out.approvals.put(at.getName(), formatValue(ca.value()));
-      }
+      Optional<LabelType> at = labelTypes.byLabel(ca.labelId());
+      at.ifPresent(lt -> out.approvals.put(lt.getName(), formatValue(ca.value())));
     }
 
     // Add dummy approvals for all permitted labels for the user even if they
@@ -125,13 +124,13 @@
         }
         for (SubmitRecord.Label label : rec.labels) {
           String name = label.label;
-          LabelType type = labelTypes.byLabel(name);
-          if (out.approvals.containsKey(name) || type == null) {
+          Optional<LabelType> type = labelTypes.byLabel(name);
+          if (out.approvals.containsKey(name) || !type.isPresent()) {
             continue;
           }
 
           try {
-            perm.check(new LabelPermission(type));
+            perm.check(new LabelPermission(type.get()));
             out.approvals.put(name, formatValue((short) 0));
           } catch (AuthException e) {
             // Do nothing.
diff --git a/java/com/google/gerrit/server/events/EventFactory.java b/java/com/google/gerrit/server/events/EventFactory.java
index 3f988a3..1bb694a 100644
--- a/java/com/google/gerrit/server/events/EventFactory.java
+++ b/java/com/google/gerrit/server/events/EventFactory.java
@@ -71,6 +71,7 @@
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.PersonIdent;
@@ -535,10 +536,8 @@
     a.grantedOn = approval.granted().getTime() / 1000L;
     a.oldValue = null;
 
-    LabelType lt = labelTypes.byLabel(approval.labelId());
-    if (lt != null) {
-      a.description = lt.getName();
-    }
+    Optional<LabelType> lt = labelTypes.byLabel(approval.labelId());
+    lt.ifPresent(l -> a.description = l.getName());
     return a;
   }
 
diff --git a/java/com/google/gerrit/server/events/StreamEventsApiListener.java b/java/com/google/gerrit/server/events/StreamEventsApiListener.java
index 439f53e..edd1928 100644
--- a/java/com/google/gerrit/server/events/StreamEventsApiListener.java
+++ b/java/com/google/gerrit/server/events/StreamEventsApiListener.java
@@ -23,7 +23,6 @@
 import com.google.gerrit.entities.Account;
 import com.google.gerrit.entities.BranchNameKey;
 import com.google.gerrit.entities.Change;
-import com.google.gerrit.entities.LabelType;
 import com.google.gerrit.entities.LabelTypes;
 import com.google.gerrit.entities.PatchSet;
 import com.google.gerrit.entities.Project;
@@ -202,10 +201,7 @@
         a.oldValue = Short.toString(oldApprovals.get(approval.getKey()));
       }
     }
-    LabelType lt = labelTypes.byLabel(approval.getKey());
-    if (lt != null) {
-      a.description = lt.getName();
-    }
+    labelTypes.byLabel(approval.getKey()).ifPresent(lt -> a.description = lt.getName());
     if (approval.getValue() != null) {
       a.value = Short.toString(approval.getValue());
     }
diff --git a/java/com/google/gerrit/server/git/MergeUtil.java b/java/com/google/gerrit/server/git/MergeUtil.java
index 1da14f8..a5ea24d 100644
--- a/java/com/google/gerrit/server/git/MergeUtil.java
+++ b/java/com/google/gerrit/server/git/MergeUtil.java
@@ -600,11 +600,11 @@
       } else if (isVerified(a.labelId())) {
         tag = "Tested-by";
       } else {
-        final LabelType lt = project.getLabelTypes().byLabel(a.labelId());
-        if (lt == null) {
+        final Optional<LabelType> lt = project.getLabelTypes().byLabel(a.labelId());
+        if (!lt.isPresent()) {
           continue;
         }
-        tag = lt.getName();
+        tag = lt.get().getName();
       }
 
       if (!contains(footers, new FooterKey(tag), identbuf.toString())) {
diff --git a/java/com/google/gerrit/server/git/receive/ReplaceOp.java b/java/com/google/gerrit/server/git/receive/ReplaceOp.java
index f00b48eb..b2a31b9 100644
--- a/java/com/google/gerrit/server/git/receive/ReplaceOp.java
+++ b/java/com/google/gerrit/server/git/receive/ReplaceOp.java
@@ -465,10 +465,10 @@
           continue;
         }
 
-        LabelType lt = projectState.getLabelTypes().byLabel(a.labelId());
-        if (lt != null) {
-          current.put(lt.getName(), a);
-        }
+        projectState
+            .getLabelTypes()
+            .byLabel(a.labelId())
+            .ifPresent(l -> current.put(l.getName(), a));
       }
     }
     return current;
diff --git a/java/com/google/gerrit/server/index/change/ChangeField.java b/java/com/google/gerrit/server/index/change/ChangeField.java
index 810cd4d..1ee12fe 100644
--- a/java/com/google/gerrit/server/index/change/ChangeField.java
+++ b/java/com/google/gerrit/server/index/change/ChangeField.java
@@ -605,7 +605,7 @@
     for (PatchSetApproval a : cd.currentApprovals()) {
       if (a.value() != 0 && !a.isLegacySubmit()) {
         allApprovals.add(formatLabel(a.label(), a.value(), a.accountId()));
-        LabelType labelType = cd.getLabelTypes().byLabel(a.labelId());
+        Optional<LabelType> labelType = cd.getLabelTypes().byLabel(a.labelId());
         allApprovals.addAll(getMaxMinAnyLabels(a.label(), a.value(), labelType, a.accountId()));
         if (owners && cd.change().getOwner().equals(a.accountId())) {
           allApprovals.add(formatLabel(a.label(), a.value(), ChangeQueryBuilder.OWNER_ACCOUNT_ID));
@@ -622,13 +622,15 @@
   }
 
   private static List<String> getMaxMinAnyLabels(
-      String label, short labelVal, LabelType labelType, @Nullable Account.Id accountId) {
+      String label, short labelVal, Optional<LabelType> labelType, @Nullable Account.Id accountId) {
     List<String> labels = new ArrayList<>();
-    if (labelVal == labelType.getMaxPositive()) {
-      labels.add(formatLabel(label, MagicLabelValue.MAX.name(), accountId));
-    }
-    if (labelVal == labelType.getMaxNegative()) {
-      labels.add(formatLabel(label, MagicLabelValue.MIN.name(), accountId));
+    if (labelType.isPresent()) {
+      if (labelVal == labelType.get().getMaxPositive()) {
+        labels.add(formatLabel(label, MagicLabelValue.MAX.name(), accountId));
+      }
+      if (labelVal == labelType.get().getMaxNegative()) {
+        labels.add(formatLabel(label, MagicLabelValue.MIN.name(), accountId));
+      }
     }
     labels.add(formatLabel(label, MagicLabelValue.ANY.name(), accountId));
     return labels;
diff --git a/java/com/google/gerrit/server/mail/send/MergedSender.java b/java/com/google/gerrit/server/mail/send/MergedSender.java
index 6af2345..56528df 100644
--- a/java/com/google/gerrit/server/mail/send/MergedSender.java
+++ b/java/com/google/gerrit/server/mail/send/MergedSender.java
@@ -79,14 +79,14 @@
       Table<Account.Id, String, PatchSetApproval> pos = HashBasedTable.create();
       Table<Account.Id, String, PatchSetApproval> neg = HashBasedTable.create();
       for (PatchSetApproval ca : args.approvalsUtil.byPatchSet(changeData.notes(), patchSet.id())) {
-        LabelType lt = labelTypes.byLabel(ca.labelId());
-        if (lt == null) {
+        Optional<LabelType> lt = labelTypes.byLabel(ca.labelId());
+        if (!lt.isPresent()) {
           continue;
         }
         if (ca.value() > 0) {
-          pos.put(ca.accountId(), lt.getName(), ca);
+          pos.put(ca.accountId(), lt.get().getName(), ca);
         } else if (ca.value() < 0) {
-          neg.put(ca.accountId(), lt.getName(), ca);
+          neg.put(ca.accountId(), lt.get().getName(), ca);
         }
       }
 
diff --git a/java/com/google/gerrit/server/patch/SubmitWithStickyApprovalDiff.java b/java/com/google/gerrit/server/patch/SubmitWithStickyApprovalDiff.java
index e33b261..62cfa47 100644
--- a/java/com/google/gerrit/server/patch/SubmitWithStickyApprovalDiff.java
+++ b/java/com/google/gerrit/server/patch/SubmitWithStickyApprovalDiff.java
@@ -18,6 +18,7 @@
 
 import com.google.gerrit.common.data.PatchScript;
 import com.google.gerrit.entities.LabelId;
+import com.google.gerrit.entities.LabelType;
 import com.google.gerrit.entities.Patch;
 import com.google.gerrit.entities.Patch.ChangeType;
 import com.google.gerrit.entities.PatchSet;
@@ -43,6 +44,7 @@
 import java.io.IOException;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.stream.Collectors;
 import org.eclipse.jgit.diff.Edit;
 import org.eclipse.jgit.lib.Config;
@@ -242,10 +244,9 @@
       if (!patchSetApproval.label().equals(LabelId.CODE_REVIEW)) {
         continue;
       }
-      if (!projectState
-          .getLabelTypes(notes)
-          .byLabel(patchSetApproval.labelId())
-          .isMaxPositive(patchSetApproval)) {
+      Optional<LabelType> lt =
+          projectState.getLabelTypes(notes).byLabel(patchSetApproval.labelId());
+      if (!lt.isPresent() || !lt.get().isMaxPositive(patchSetApproval)) {
         continue;
       }
       if (patchSetApproval.patchSetId().get() > maxPatchSetId.get()) {
diff --git a/java/com/google/gerrit/server/patch/diff/ModifiedFilesCacheImpl.java b/java/com/google/gerrit/server/patch/diff/ModifiedFilesCacheImpl.java
index b779bf7..e4fd728 100644
--- a/java/com/google/gerrit/server/patch/diff/ModifiedFilesCacheImpl.java
+++ b/java/com/google/gerrit/server/patch/diff/ModifiedFilesCacheImpl.java
@@ -18,11 +18,14 @@
 
 import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
+import com.google.common.collect.ArrayListMultimap;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ListMultimap;
 import com.google.common.collect.Sets;
 import com.google.common.collect.Streams;
 import com.google.common.flogger.FluentLogger;
+import com.google.gerrit.entities.Patch.ChangeType;
 import com.google.gerrit.server.cache.CacheModule;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.patch.DiffNotAvailableException;
@@ -37,6 +40,7 @@
 import com.google.inject.TypeLiteral;
 import com.google.inject.name.Named;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
 import java.util.stream.Stream;
@@ -82,7 +86,7 @@
             .valueSerializer(GitModifiedFilesCacheImpl.ValueSerializer.INSTANCE)
             .maximumWeight(10 << 20)
             .weigher(ModifiedFilesWeigher.class)
-            .version(1)
+            .version(2)
             .loader(ModifiedFilesLoader.class);
       }
     };
@@ -139,7 +143,7 @@
               .bTree(bTree)
               .renameScore(key.renameScore())
               .build();
-      List<ModifiedFile> modifiedFiles = gitCache.get(gitKey);
+      List<ModifiedFile> modifiedFiles = mergeRewrittenEntries(gitCache.get(gitKey));
       if (key.aCommit().equals(ObjectId.zeroId())) {
         return ImmutableList.copyOf(modifiedFiles);
       }
@@ -202,5 +206,61 @@
       // value as the set of file paths shouldn't contain it.
       return touchedFilePaths.contains(oldFilePath) || touchedFilePaths.contains(newFilePath);
     }
+
+    /**
+     * Return the {@code modifiedFiles} input list while merging {@link ChangeType#ADDED} and {@link
+     * ChangeType#DELETED} entries for the same file into a single {@link ChangeType#REWRITE} entry.
+     *
+     * <p>Background: In some cases, JGit returns two diff entries (ADDED + DELETED) for the same
+     * file path. This happens e.g. when a file's mode is changed between patchsets, for example
+     * converting a symlink file to a regular file. We identify this case and return a single
+     * modified file with changeType = {@link ChangeType#REWRITE}.
+     */
+    private static List<ModifiedFile> mergeRewrittenEntries(List<ModifiedFile> modifiedFiles) {
+      List<ModifiedFile> result = new ArrayList<>();
+
+      // Handle ADDED and DELETED entries separately.
+      ListMultimap<String, ModifiedFile> byPath = ArrayListMultimap.create();
+      modifiedFiles.stream()
+          .filter(ModifiedFilesLoader::isAddedOrDeleted)
+          .forEach(
+              f -> {
+                if (f.oldPath().isPresent()) {
+                  byPath.get(f.oldPath().get()).add(f);
+                }
+                if (f.newPath().isPresent()) {
+                  byPath.get(f.newPath().get()).add(f);
+                }
+              });
+      for (String path : byPath.keySet()) {
+        List<ModifiedFile> entries = byPath.get(path);
+        if (entries.size() == 1) {
+          result.add(entries.get(0));
+        } else if (entries.size() == 2) {
+          result.add(getAddedEntry(entries).toBuilder().changeType(ChangeType.REWRITE).build());
+        } else {
+          // JGit error. Not expected to happen.
+          logger.atWarning().log(
+              "Found %d ADDED and DELETED entries for the same file path: %s."
+                  + " Adding the first entry only to the result.",
+              entries.size(), entries);
+          result.add(entries.get(0));
+        }
+      }
+
+      // Add the remaining non ADDED/DELETED entries to the result
+      modifiedFiles.stream().filter(f -> !isAddedOrDeleted(f)).forEach(result::add);
+      return result;
+    }
+
+    private static boolean isAddedOrDeleted(ModifiedFile f) {
+      return f.changeType() == ChangeType.ADDED || f.changeType() == ChangeType.DELETED;
+    }
+
+    private static ModifiedFile getAddedEntry(List<ModifiedFile> modifiedFiles) {
+      return modifiedFiles.get(0).changeType() == ChangeType.ADDED
+          ? modifiedFiles.get(0)
+          : modifiedFiles.get(1);
+    }
   }
 }
diff --git a/java/com/google/gerrit/server/patch/gitdiff/ModifiedFile.java b/java/com/google/gerrit/server/patch/gitdiff/ModifiedFile.java
index 9512094..f4e7ca3 100644
--- a/java/com/google/gerrit/server/patch/gitdiff/ModifiedFile.java
+++ b/java/com/google/gerrit/server/patch/gitdiff/ModifiedFile.java
@@ -51,6 +51,8 @@
     return new AutoValue_ModifiedFile.Builder();
   }
 
+  public abstract Builder toBuilder();
+
   /** Computes this object's weight, which is its size in bytes. */
   public int weight() {
     int weight = 1; // the changeType field
diff --git a/java/com/google/gerrit/server/patch/gitfilediff/GitFileDiff.java b/java/com/google/gerrit/server/patch/gitfilediff/GitFileDiff.java
index 2f2d29b..a502a46 100644
--- a/java/com/google/gerrit/server/patch/gitfilediff/GitFileDiff.java
+++ b/java/com/google/gerrit/server/patch/gitfilediff/GitFileDiff.java
@@ -187,6 +187,10 @@
     return result;
   }
 
+  public String getDefaultPath() {
+    return oldPath().isPresent() ? oldPath().get() : newPath().get();
+  }
+
   public static Builder builder() {
     return new AutoValue_GitFileDiff.Builder();
   }
diff --git a/java/com/google/gerrit/server/patch/gitfilediff/GitFileDiffCacheImpl.java b/java/com/google/gerrit/server/patch/gitfilediff/GitFileDiffCacheImpl.java
index 2ce6925..77b8938 100644
--- a/java/com/google/gerrit/server/patch/gitfilediff/GitFileDiffCacheImpl.java
+++ b/java/com/google/gerrit/server/patch/gitfilediff/GitFileDiffCacheImpl.java
@@ -24,7 +24,11 @@
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
+import com.google.common.collect.ListMultimap;
+import com.google.common.collect.MultimapBuilder;
+import com.google.common.collect.Multimaps;
 import com.google.common.collect.Streams;
+import com.google.gerrit.entities.Patch;
 import com.google.gerrit.entities.Project;
 import com.google.gerrit.extensions.client.DiffPreferencesInfo.Whitespace;
 import com.google.gerrit.server.cache.CacheModule;
@@ -41,6 +45,7 @@
 import com.google.inject.Singleton;
 import com.google.inject.name.Named;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
@@ -105,6 +110,9 @@
 
   private final LoadingCache<GitFileDiffCacheKey, GitFileDiff> cache;
 
+  private static final ImmutableSet<Patch.ChangeType> ADDED_AND_DELETED =
+      ImmutableSet.of(Patch.ChangeType.ADDED, Patch.ChangeType.DELETED);
+
   @Inject
   public GitFileDiffCacheImpl(
       @Named(GIT_DIFF) LoadingCache<GitFileDiffCacheKey, GitFileDiff> cache) {
@@ -163,7 +171,7 @@
     }
 
     @Override
-    public GitFileDiff load(GitFileDiffCacheKey key) throws IOException {
+    public GitFileDiff load(GitFileDiffCacheKey key) throws IOException, DiffNotAvailableException {
       try (TraceTimer timer =
           TraceContext.newTimer(
               "Loading a single key from git file diff cache",
@@ -177,7 +185,8 @@
 
     @Override
     public Map<GitFileDiffCacheKey, GitFileDiff> loadAll(
-        Iterable<? extends GitFileDiffCacheKey> keys) throws IOException {
+        Iterable<? extends GitFileDiffCacheKey> keys)
+        throws IOException, DiffNotAvailableException {
       try (TraceTimer timer =
           TraceContext.newTimer("Loading multiple keys from git file diff cache")) {
         ImmutableMap.Builder<GitFileDiffCacheKey, GitFileDiff> result =
@@ -215,13 +224,14 @@
      */
     private Map<GitFileDiffCacheKey, GitFileDiff> loadAllImpl(
         Repository repo, ObjectReader reader, DiffOptions options, List<GitFileDiffCacheKey> keys)
-        throws IOException {
+        throws IOException, DiffNotAvailableException {
       ImmutableMap.Builder<GitFileDiffCacheKey, GitFileDiff> result =
           ImmutableMap.builderWithExpectedSize(keys.size());
       Map<GitFileDiffCacheKey, String> filePaths =
           keys.stream().collect(Collectors.toMap(identity(), GitFileDiffCacheKey::newFilePath));
       DiffFormatter formatter = createDiffFormatter(options, repo, reader);
-      Map<String, DiffEntry> diffEntries = loadDiffEntries(formatter, options, filePaths.values());
+      ListMultimap<String, DiffEntry> diffEntries =
+          loadDiffEntries(formatter, options, filePaths.values());
       for (GitFileDiffCacheKey key : filePaths.keySet()) {
         String newFilePath = filePaths.get(key);
         if (!diffEntries.containsKey(newFilePath)) {
@@ -233,14 +243,25 @@
                   newFilePath));
           continue;
         }
-        DiffEntry diffEntry = diffEntries.get(newFilePath);
-        GitFileDiff gitFileDiff = createGitFileDiff(diffEntry, formatter, key);
-        result.put(key, gitFileDiff);
+        List<DiffEntry> entries = diffEntries.get(newFilePath);
+        if (entries.size() == 1) {
+          result.put(key, createGitFileDiff(entries.get(0), formatter, key));
+        } else {
+          // Handle when JGit returns two {Added, Deleted} entries for the same file. This happens,
+          // for example, when a file's mode is changed between patchsets (e.g. converting a
+          // symlink to a regular file). We combine both diff entries into a single entry with
+          // {changeType = Rewrite}.
+          List<GitFileDiff> gitDiffs = new ArrayList<>();
+          for (DiffEntry entry : diffEntries.get(newFilePath)) {
+            gitDiffs.add(createGitFileDiff(entry, formatter, key));
+          }
+          result.put(key, createRewriteEntry(gitDiffs));
+        }
       }
       return result.build();
     }
 
-    private static Map<String, DiffEntry> loadDiffEntries(
+    private static ListMultimap<String, DiffEntry> loadDiffEntries(
         DiffFormatter diffFormatter, DiffOptions diffOptions, Collection<String> filePaths)
         throws IOException {
       Set<String> filePathsSet = ImmutableSet.copyOf(filePaths);
@@ -251,7 +272,11 @@
 
       return diffEntries.stream()
           .filter(d -> filePathsSet.contains(pathExtractor.apply(d)))
-          .collect(Collectors.toMap(d -> pathExtractor.apply(d), identity()));
+          .collect(
+              Multimaps.toMultimap(
+                  d -> pathExtractor.apply(d),
+                  identity(),
+                  MultimapBuilder.treeKeys().arrayListValues()::build));
     }
 
     private static DiffFormatter createDiffFormatter(
@@ -334,6 +359,39 @@
     }
   }
 
+  /**
+   * Create a single {@link GitFileDiff} with {@link Patch.ChangeType} equals {@link
+   * Patch.ChangeType#REWRITE}, assuming the input list contains two entries with types {@link
+   * Patch.ChangeType#ADDED} and {@link Patch.ChangeType#DELETED}.
+   *
+   * @param gitDiffs input list of exactly two {@link GitFileDiff} for same file path.
+   * @return a single {@link GitFileDiff} with change type equals {@link Patch.ChangeType#REWRITE}.
+   * @throws DiffNotAvailableException if input list contains git diffs with change types other than
+   *     {ADDED, DELETED}. This is a JGit error.
+   */
+  private static GitFileDiff createRewriteEntry(List<GitFileDiff> gitDiffs)
+      throws DiffNotAvailableException {
+    if (gitDiffs.size() != 2) {
+      throw new DiffNotAvailableException(
+          String.format(
+              "JGit error: found %d dff entries for same file path %s",
+              gitDiffs.size(), gitDiffs.get(0).getDefaultPath()));
+    }
+    if (!ImmutableSet.of(gitDiffs.get(0).changeType(), gitDiffs.get(1).changeType())
+        .equals(ADDED_AND_DELETED)) {
+      // This is an illegal state. JGit is not supposed to return this, so we throw an exception.
+      throw new DiffNotAvailableException(
+          String.format(
+              "JGit error: unexpected change types %s and %s for same file path %s",
+              gitDiffs.get(0).changeType(),
+              gitDiffs.get(1).changeType(),
+              gitDiffs.get(0).getDefaultPath()));
+    }
+    GitFileDiff addedEntry =
+        gitDiffs.get(0).changeType() == Patch.ChangeType.ADDED ? gitDiffs.get(0) : gitDiffs.get(1);
+    return addedEntry.toBuilder().changeType(Patch.ChangeType.REWRITE).build();
+  }
+
   /** An entity representing the options affecting the diff computation. */
   @AutoValue
   abstract static class DiffOptions {
diff --git a/java/com/google/gerrit/server/query/approval/MagicValuePredicate.java b/java/com/google/gerrit/server/query/approval/MagicValuePredicate.java
index 2924e6e..326620d 100644
--- a/java/com/google/gerrit/server/query/approval/MagicValuePredicate.java
+++ b/java/com/google/gerrit/server/query/approval/MagicValuePredicate.java
@@ -23,6 +23,7 @@
 import com.google.inject.assistedinject.Assisted;
 import java.util.Collection;
 import java.util.Objects;
+import java.util.Optional;
 
 /** Predicate that matches patch set approvals we want to copy based on the value. */
 public class MagicValuePredicate extends ApprovalPredicate {
@@ -47,19 +48,23 @@
 
   @Override
   public boolean match(ApprovalContext ctx) {
+    Optional<LabelType> lt =
+        getLabelType(ctx.changeNotes().getProjectName(), ctx.patchSetApproval().labelId());
     short pValue;
     switch (value) {
       case ANY:
         return true;
       case MIN:
-        pValue =
-            getLabelType(ctx.changeNotes().getProjectName(), ctx.patchSetApproval().labelId())
-                .getMaxNegative();
+        if (!lt.isPresent()) {
+          return false;
+        }
+        pValue = lt.get().getMaxNegative();
         break;
       case MAX:
-        pValue =
-            getLabelType(ctx.changeNotes().getProjectName(), ctx.patchSetApproval().labelId())
-                .getMaxPositive();
+        if (!lt.isPresent()) {
+          return false;
+        }
+        pValue = lt.get().getMaxPositive();
         break;
       default:
         throw new IllegalArgumentException("unrecognized label value: " + value);
@@ -67,7 +72,7 @@
     return pValue == ctx.patchSetApproval().value();
   }
 
-  private LabelType getLabelType(Project.NameKey project, LabelId labelId) {
+  private Optional<LabelType> getLabelType(Project.NameKey project, LabelId labelId) {
     return projectCache
         .get(project)
         .orElseThrow(() -> new IllegalStateException(project + " absent"))
diff --git a/java/com/google/gerrit/server/query/change/EqualsLabelPredicate.java b/java/com/google/gerrit/server/query/change/EqualsLabelPredicate.java
index 30d5e2f..ade615c 100644
--- a/java/com/google/gerrit/server/query/change/EqualsLabelPredicate.java
+++ b/java/com/google/gerrit/server/query/change/EqualsLabelPredicate.java
@@ -91,8 +91,8 @@
   }
 
   protected static LabelType type(LabelTypes types, String toFind) {
-    if (types.byLabel(toFind) != null) {
-      return types.byLabel(toFind);
+    if (types.byLabel(toFind).isPresent()) {
+      return types.byLabel(toFind).get();
     }
 
     for (LabelType lt : types.getLabelTypes()) {
diff --git a/java/com/google/gerrit/server/query/change/MagicLabelPredicate.java b/java/com/google/gerrit/server/query/change/MagicLabelPredicate.java
index e3c58e47..2c56322 100644
--- a/java/com/google/gerrit/server/query/change/MagicLabelPredicate.java
+++ b/java/com/google/gerrit/server/query/change/MagicLabelPredicate.java
@@ -87,8 +87,8 @@
   }
 
   protected static LabelType type(LabelTypes types, String toFind) {
-    if (types.byLabel(toFind) != null) {
-      return types.byLabel(toFind);
+    if (types.byLabel(toFind).isPresent()) {
+      return types.byLabel(toFind).get();
     }
 
     for (LabelType lt : types.getLabelTypes()) {
diff --git a/java/com/google/gerrit/server/restapi/change/DeleteVote.java b/java/com/google/gerrit/server/restapi/change/DeleteVote.java
index 84424a8..2c358d0 100644
--- a/java/com/google/gerrit/server/restapi/change/DeleteVote.java
+++ b/java/com/google/gerrit/server/restapi/change/DeleteVote.java
@@ -194,7 +194,7 @@
       for (PatchSetApproval a :
           approvalsUtil.byPatchSetUser(
               ctx.getNotes(), psId, accountId, ctx.getRevWalk(), ctx.getRepoView().getConfig())) {
-        if (labelTypes.byLabel(a.labelId()) == null) {
+        if (!labelTypes.byLabel(a.labelId()).isPresent()) {
           continue; // Ignore undefined labels.
         } else if (!a.label().equals(label)) {
           // Populate map for non-matching labels, needed by VoteDeleted.
diff --git a/java/com/google/gerrit/server/restapi/change/Move.java b/java/com/google/gerrit/server/restapi/change/Move.java
index 9263971..8c21841 100644
--- a/java/com/google/gerrit/server/restapi/change/Move.java
+++ b/java/com/google/gerrit/server/restapi/change/Move.java
@@ -64,6 +64,7 @@
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
+import java.util.Optional;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Repository;
@@ -265,11 +266,13 @@
           approvalsUtil.byPatchSet(
               ctx.getNotes(), psId, ctx.getRevWalk(), ctx.getRepoView().getConfig())) {
         ProjectState projectState = projectCache.get(project).orElseThrow(illegalState(project));
-        LabelType type = projectState.getLabelTypes(ctx.getNotes()).byLabel(psa.labelId());
+        Optional<LabelType> type =
+            projectState.getLabelTypes(ctx.getNotes()).byLabel(psa.labelId());
         // Only keep veto votes, defined as votes where:
         // 1- the label function allows minimum values to block submission.
         // 2- the vote holds the minimum value.
-        if (type == null || (type.isMaxNegative(psa) && type.getFunction().isBlock())) {
+        if (!type.isPresent()
+            || (type.get().isMaxNegative(psa) && type.get().getFunction().isBlock())) {
           continue;
         }
 
diff --git a/java/com/google/gerrit/server/restapi/change/PostReview.java b/java/com/google/gerrit/server/restapi/change/PostReview.java
index 6816361..4dbb6ee 100644
--- a/java/com/google/gerrit/server/restapi/change/PostReview.java
+++ b/java/com/google/gerrit/server/restapi/change/PostReview.java
@@ -22,7 +22,6 @@
 import static com.google.gerrit.server.permissions.LabelPermission.ForUser.ON_BEHALF_OF;
 import static com.google.gerrit.server.project.ProjectCache.illegalState;
 import static java.nio.charset.StandardCharsets.UTF_8;
-import static java.util.Objects.requireNonNull;
 import static java.util.stream.Collectors.groupingBy;
 import static java.util.stream.Collectors.joining;
 import static java.util.stream.Collectors.toList;
@@ -502,8 +501,8 @@
     Iterator<Map.Entry<String, Short>> itr = in.labels.entrySet().iterator();
     while (itr.hasNext()) {
       Map.Entry<String, Short> ent = itr.next();
-      LabelType type = labelTypes.byLabel(ent.getKey());
-      if (type == null) {
+      Optional<LabelType> type = labelTypes.byLabel(ent.getKey());
+      if (!type.isPresent()) {
         logger.atFine().log("label %s not found", ent.getKey());
         if (strictLabels) {
           throw new BadRequestException(
@@ -518,15 +517,15 @@
         logger.atFine().log(
             "skipping on behalf of permission check for label %s"
                 + " because caller is an internal user",
-            type.getName());
+            type.get().getName());
       } else {
         try {
-          perm.check(new LabelPermission.WithValue(ON_BEHALF_OF, type, ent.getValue()));
+          perm.check(new LabelPermission.WithValue(ON_BEHALF_OF, type.get(), ent.getValue()));
         } catch (AuthException e) {
           throw new AuthException(
               String.format(
                   "not permitted to modify label \"%s\" on behalf of \"%s\"",
-                  type.getName(), in.onBehalfOf),
+                  type.get().getName(), in.onBehalfOf),
               e);
         }
       }
@@ -558,8 +557,8 @@
     Iterator<Map.Entry<String, Short>> itr = labels.entrySet().iterator();
     while (itr.hasNext()) {
       Map.Entry<String, Short> ent = itr.next();
-      LabelType lt = labelTypes.byLabel(ent.getKey());
-      if (lt == null) {
+      Optional<LabelType> lt = labelTypes.byLabel(ent.getKey());
+      if (!lt.isPresent()) {
         logger.atFine().log("label %s not found", ent.getKey());
         if (strictLabels) {
           throw new BadRequestException(
@@ -576,7 +575,7 @@
         continue;
       }
 
-      if (lt.getValue(ent.getValue()) == null) {
+      if (lt.get().getValue(ent.getValue()) == null) {
         logger.atFine().log("label value %s not found", ent.getValue());
         if (strictLabels) {
           throw new BadRequestException(
@@ -590,10 +589,10 @@
 
       short val = ent.getValue();
       try {
-        perm.check(new LabelPermission.WithValue(lt, val));
+        perm.check(new LabelPermission.WithValue(lt.get(), val));
       } catch (AuthException e) {
         throw new AuthException(
-            String.format("Applying label \"%s\": %d is restricted", lt.getName(), val), e);
+            String.format("Applying label \"%s\": %d is restricted", lt.get().getName(), val), e);
       }
     }
   }
@@ -1356,7 +1355,10 @@
       ChangeUpdate update = ctx.getUpdate(psId);
       for (Map.Entry<String, Short> ent : allApprovals.entrySet()) {
         String name = ent.getKey();
-        LabelType lt = requireNonNull(labelTypes.byLabel(name), name);
+        LabelType lt =
+            labelTypes
+                .byLabel(name)
+                .orElseThrow(() -> new IllegalStateException("no label config for " + name));
 
         PatchSetApproval c = current.remove(lt.getName());
         String normName = lt.getName();
@@ -1448,7 +1450,10 @@
       List<String> disallowed = new ArrayList<>(labelTypes.getLabelTypes().size());
 
       for (PatchSetApproval psa : del) {
-        LabelType lt = requireNonNull(labelTypes.byLabel(psa.label()));
+        LabelType lt =
+            labelTypes
+                .byLabel(psa.label())
+                .orElseThrow(() -> new IllegalStateException("no label config for " + psa.label()));
         String normName = lt.getName();
         if (!lt.isAllowPostSubmit()) {
           disallowed.add(normName);
@@ -1460,7 +1465,10 @@
       }
 
       for (PatchSetApproval psa : ups) {
-        LabelType lt = requireNonNull(labelTypes.byLabel(psa.label()));
+        LabelType lt =
+            labelTypes
+                .byLabel(psa.label())
+                .orElseThrow(() -> new IllegalStateException("no label config for " + psa.label()));
         String normName = lt.getName();
         if (!lt.isAllowPostSubmit()) {
           disallowed.add(normName);
@@ -1508,9 +1516,9 @@
           continue;
         }
 
-        LabelType lt = labelTypes.byLabel(a.labelId());
-        if (lt != null) {
-          current.put(lt.getName(), a);
+        Optional<LabelType> lt = labelTypes.byLabel(a.labelId());
+        if (lt.isPresent()) {
+          current.put(lt.get().getName(), a);
         } else {
           del.add(a);
         }
diff --git a/java/gerrit/PRED__load_commit_labels_1.java b/java/gerrit/PRED__load_commit_labels_1.java
index 5ee292ff..9a656b8 100644
--- a/java/gerrit/PRED__load_commit_labels_1.java
+++ b/java/gerrit/PRED__load_commit_labels_1.java
@@ -16,6 +16,7 @@
 import com.googlecode.prolog_cafe.lang.StructureTerm;
 import com.googlecode.prolog_cafe.lang.SymbolTerm;
 import com.googlecode.prolog_cafe.lang.Term;
+import java.util.Optional;
 
 /** Exports list of {@code commit_label( label('Code-Review', 2), user(12345789) )}. */
 class PRED__load_commit_labels_1 extends Predicate.P1 {
@@ -38,13 +39,14 @@
     LabelTypes types = cd.getLabelTypes();
 
     for (PatchSetApproval a : cd.currentApprovals()) {
-      LabelType t = types.byLabel(a.labelId());
-      if (t == null) {
+      Optional<LabelType> t = types.byLabel(a.labelId());
+      if (!t.isPresent()) {
         continue;
       }
 
       StructureTerm labelTerm =
-          new StructureTerm(sym_label, SymbolTerm.intern(t.getName()), new IntegerTerm(a.value()));
+          new StructureTerm(
+              sym_label, SymbolTerm.intern(t.get().getName()), new IntegerTerm(a.value()));
 
       StructureTerm userTerm = new StructureTerm(sym_user, new IntegerTerm(a.accountId().get()));
 
diff --git a/javatests/com/google/gerrit/acceptance/api/revision/RevisionDiffIT.java b/javatests/com/google/gerrit/acceptance/api/revision/RevisionDiffIT.java
index a01b340..5f3b702 100644
--- a/javatests/com/google/gerrit/acceptance/api/revision/RevisionDiffIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/revision/RevisionDiffIT.java
@@ -50,6 +50,7 @@
 import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.BinaryResult;
 import com.google.gerrit.extensions.webui.EditWebLink;
+import com.google.gerrit.server.change.FileInfoJsonExperimentImpl;
 import com.google.gerrit.server.patch.DiffOperations;
 import com.google.gerrit.server.patch.filediff.FileDiffOutput;
 import com.google.inject.Inject;
@@ -109,7 +110,8 @@
 
     intraline = baseConfig.getBoolean(TEST_PARAMETER_MARKER, "intraline", false);
     useNewDiffCacheListFiles =
-        baseConfig.getBoolean("cache", "diff_cache", "runNewDiffCache_ListFiles", false);
+        Arrays.asList(baseConfig.getStringList("experiments", null, "enabled"))
+            .contains(FileInfoJsonExperimentImpl.NEW_DIFF_CACHE_FEATURE);
     useNewDiffCacheGetDiff =
         baseConfig.getBoolean("cache", "diff_cache", "runNewDiffCache_GetDiff", false);
 
@@ -2836,11 +2838,7 @@
   }
 
   @Test
-  public void symlinkConvertedToRegularFileIsIdentifiedAsAdded() throws Exception {
-    // TODO(ghareeb): fix this test for the new diff cache implementation
-    assume().that(useNewDiffCacheListFiles).isFalse();
-    assume().that(useNewDiffCacheGetDiff).isFalse();
-
+  public void symlinkConvertedToRegularFileIsIdentifiedAsRewritten() throws Exception {
     String target = "file.txt";
     String symlink = "link.lnk";
 
@@ -2868,23 +2866,39 @@
         gApi.changes().id(result.getChangeId()).current().files(initialRev);
 
     assertThat(changedFiles.keySet()).containsExactly("/COMMIT_MSG", symlink);
-    assertThat(changedFiles.get(symlink).status).isEqualTo('W'); // Rewrite
+
+    // Both old and new diff caches agree that the state is rewritten
+    assertThat(changedFiles.get(symlink).status).isEqualTo('W'); // Rewritten
 
     DiffInfo diffInfo =
         gApi.changes().id(result.getChangeId()).current().file(symlink).diff(initialRev);
 
-    // The diff logic identifies two entries for the file:
-    // 1. One entry as 'DELETED' for the symlink.
-    // 2. Another entry as 'ADDED' for the new regular file.
-    // Since the diff logic returns a single entry, we prioritize returning the 'ADDED' entry in
-    // this case so that the client is able to see the new content that was added to the file.
-    assertThat(diffInfo.changeType).isEqualTo(ChangeType.ADDED);
-    assertThat(diffInfo.content).hasSize(1);
-    assertThat(diffInfo)
-        .content()
-        .element(0)
-        .linesOfB()
-        .containsExactly("Content of the new file named 'symlink'");
+    // TODO(ghareeb): Remove the else branch when the new diff cache is rolled out as default.
+    if (useNewDiffCacheGetDiff) {
+      // File diff in New diff cache: change type is correctly identified as REWRITTEN
+      assertThat(diffInfo.changeType).isEqualTo(ChangeType.REWRITE);
+      assertThat(diffInfo.content).hasSize(2);
+      assertThat(diffInfo)
+          .content()
+          .element(0)
+          .linesOfB()
+          .containsExactly("Content of the new file named 'symlink'");
+      assertThat(diffInfo).content().element(1).linesOfA().containsExactly("file.txt");
+    } else {
+      // File diff in old diff cache: The diff logic identifies two entries for the file:
+      // 1. One entry as 'DELETED' for the symlink.
+      // 2. Another entry as 'ADDED' for the new regular file.
+      // Since the diff logic returns a single entry, the implementation prioritizes  the 'ADDED'
+      // entry in this case so that the user is able to see the new content that was added to the
+      // file.
+      assertThat(diffInfo.changeType).isEqualTo(ChangeType.ADDED);
+      assertThat(diffInfo.content).hasSize(1);
+      assertThat(diffInfo)
+          .content()
+          .element(0)
+          .linesOfB()
+          .containsExactly("Content of the new file named 'symlink'");
+    }
   }
 
   @Test
diff --git a/javatests/com/google/gerrit/acceptance/api/revision/RevisionNewDiffCacheIT.java b/javatests/com/google/gerrit/acceptance/api/revision/RevisionNewDiffCacheIT.java
index ec0bcc6..714bd78 100644
--- a/javatests/com/google/gerrit/acceptance/api/revision/RevisionNewDiffCacheIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/revision/RevisionNewDiffCacheIT.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.acceptance.api.revision;
 
+import com.google.gerrit.server.change.FileInfoJsonExperimentImpl;
 import com.google.gerrit.testing.ConfigSuite;
 import org.eclipse.jgit.lib.Config;
 
@@ -26,7 +27,8 @@
   @ConfigSuite.Default
   public static Config newDiffCacheConfig() {
     Config config = new Config();
-    config.setBoolean("cache", "diff_cache", "runNewDiffCache_ListFiles", true);
+    config.setString(
+        "experiments", null, "enabled", FileInfoJsonExperimentImpl.NEW_DIFF_CACHE_FEATURE);
     return config;
   }
 }
diff --git a/javatests/com/google/gerrit/server/schema/SchemaCreatorImplTest.java b/javatests/com/google/gerrit/server/schema/SchemaCreatorImplTest.java
index fc6b412..9cba362 100644
--- a/javatests/com/google/gerrit/server/schema/SchemaCreatorImplTest.java
+++ b/javatests/com/google/gerrit/server/schema/SchemaCreatorImplTest.java
@@ -72,7 +72,7 @@
 
   @Test
   public void createSchema_Label_CodeReview() throws Exception {
-    LabelType codeReview = getLabelTypes().byLabel("Code-Review");
+    LabelType codeReview = getLabelTypes().byLabel("Code-Review").get();
     assertThat(codeReview).isNotNull();
     assertThat(codeReview.getName()).isEqualTo("Code-Review");
     assertThat(codeReview.getDefaultValue()).isEqualTo(0);
diff --git a/plugins/reviewnotes b/plugins/reviewnotes
index 35e6449..a28ae59 160000
--- a/plugins/reviewnotes
+++ b/plugins/reviewnotes
@@ -1 +1 @@
-Subproject commit 35e6449a517691a880c94e7467bc07360f8e6666
+Subproject commit a28ae590486934690e4e0a95d7eb75f8b60644a6
diff --git a/plugins/webhooks b/plugins/webhooks
index 9fc9c2d..73f9dc7 160000
--- a/plugins/webhooks
+++ b/plugins/webhooks
@@ -1 +1 @@
-Subproject commit 9fc9c2d4e69f7e2701cbcd873977d3312a231a81
+Subproject commit 73f9dc72bd52f5d64853db31e711717a995f0a46
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector.ts b/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector.ts
index b576896..0f8752d 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector.ts
@@ -43,6 +43,9 @@
   @property({type: Boolean})
   saveOnChange = false;
 
+  @property({type: Boolean})
+  showTooltipBelow = false;
+
   private readonly restApiService = appContext.restApiService;
 
   /** @override */
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector_html.ts b/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector_html.ts
index 9943b58..3ebb58f 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector_html.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector_html.ts
@@ -34,6 +34,7 @@
     id="sideBySideBtn"
     link=""
     has-tooltip=""
+    position-below="[[showTooltipBelow]]"
     class$="[[_computeSideBySideSelected(mode)]]"
     title="Side-by-side diff"
     aria-pressed="[[isSideBySideSelected(mode)]]"
@@ -45,6 +46,7 @@
     id="unifiedBtn"
     link=""
     has-tooltip=""
+    position-below="[[showTooltipBelow]]"
     title="Unified diff"
     class$="[[_computeUnifiedSelected(mode)]]"
     aria-pressed="[[isUnifiedSelected(mode)]]"
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_html.ts b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_html.ts
index 8d69007d..743f905 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_html.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_html.ts
@@ -343,6 +343,7 @@
             id="modeSelect"
             save-on-change="[[!_diffPrefsDisabled]]"
             mode="{{changeViewState.diffMode}}"
+            show-tooltip-below=""
           ></gr-diff-mode-selector>
         </div>
         <span
@@ -355,6 +356,7 @@
               link=""
               class="prefsButton"
               has-tooltip=""
+              position-below=""
               title="Diff preferences"
               on-click="_handlePrefsTap"
               ><iron-icon icon="gr-icons:settings"></iron-icon
diff --git a/polygerrit-ui/app/elements/shared/gr-account-label/gr-account-label.ts b/polygerrit-ui/app/elements/shared/gr-account-label/gr-account-label.ts
index 66214b4..1a340b9 100644
--- a/polygerrit-ui/app/elements/shared/gr-account-label/gr-account-label.ts
+++ b/polygerrit-ui/app/elements/shared/gr-account-label/gr-account-label.ts
@@ -198,7 +198,7 @@
               .account="${account}"
               .change="${change}"
               ?highlight-attention=${highlightAttention}
-              .voteable-text=${this.voteableText}
+              .voteableText=${this.voteableText}
             ></gr-hovercard-account>`
           : ''}
         ${hasAttention
diff --git a/polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar_test.js b/polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar_test.ts
similarity index 60%
rename from polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar_test.js
rename to polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar_test.ts
index df8632f..bb70855 100644
--- a/polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar_test.js
+++ b/polygerrit-ui/app/elements/shared/gr-avatar/gr-avatar_test.ts
@@ -15,19 +15,26 @@
  * limitations under the License.
  */
 
-import '../../../test/common-test-setup-karma.js';
-import './gr-avatar.js';
-import {getPluginLoader} from '../gr-js-api-interface/gr-plugin-loader.js';
-import {appContext} from '../../../services/app-context.js';
+import '../../../test/common-test-setup-karma';
+import './gr-avatar';
+import {GrAvatar} from './gr-avatar';
+import {getPluginLoader} from '../gr-js-api-interface/gr-plugin-loader';
+import {appContext} from '../../../services/app-context';
+import {AvatarInfo} from '../../../types/common';
+import {
+  createAccountWithEmail,
+  createAccountWithId,
+} from '../../../test/test-data-generators';
 
 const basicFixture = fixtureFromElement('gr-avatar');
 
 suite('gr-avatar tests', () => {
-  let element;
-  const defaultAvatars = [
+  let element: GrAvatar;
+  const defaultAvatars: AvatarInfo[] = [
     {
       url: 'https://cdn.example.com/s12-p/photo.jpg',
       height: 12,
+      width: 0,
     },
   ];
 
@@ -36,68 +43,74 @@
   });
 
   test('account without avatar', () => {
-    assert.equal(
-        element._buildAvatarURL({
-          _account_id: 123,
-        }),
-        '');
+    assert.equal(element._buildAvatarURL(createAccountWithId(123)), '');
   });
 
   test('methods', () => {
     assert.equal(
-        element._buildAvatarURL({
-          _account_id: 123,
-          avatars: defaultAvatars,
-        }),
-        '/accounts/123/avatar?s=16');
+      element._buildAvatarURL({
+        ...createAccountWithId(123),
+        avatars: defaultAvatars,
+      }),
+      '/accounts/123/avatar?s=16'
+    );
     assert.equal(
-        element._buildAvatarURL({
-          email: 'test@example.com',
-          avatars: defaultAvatars,
-        }),
-        '/accounts/test%40example.com/avatar?s=16');
+      element._buildAvatarURL({
+        ...createAccountWithEmail('test@example.com'),
+        avatars: defaultAvatars,
+      }),
+      '/accounts/test%40example.com/avatar?s=16'
+    );
     assert.equal(
-        element._buildAvatarURL({
-          name: 'John Doe',
-          avatars: defaultAvatars,
-        }),
-        '/accounts/John%20Doe/avatar?s=16');
+      element._buildAvatarURL({
+        name: 'John Doe',
+        avatars: defaultAvatars,
+      }),
+      '/accounts/John%20Doe/avatar?s=16'
+    );
     assert.equal(
-        element._buildAvatarURL({
-          username: 'John_Doe',
-          avatars: defaultAvatars,
-        }),
-        '/accounts/John_Doe/avatar?s=16');
+      element._buildAvatarURL({
+        username: 'John_Doe',
+        avatars: defaultAvatars,
+      }),
+      '/accounts/John_Doe/avatar?s=16'
+    );
     assert.equal(
-        element._buildAvatarURL({
-          _account_id: 123,
-          avatars: [
-            {
-              url: 'https://cdn.example.com/s12-p/photo.jpg',
-              height: 12,
-            },
-            {
-              url: 'https://cdn.example.com/s16-p/photo.jpg',
-              height: 16,
-            },
-            {
-              url: 'https://cdn.example.com/s100-p/photo.jpg',
-              height: 100,
-            },
-          ],
-        }),
-        'https://cdn.example.com/s16-p/photo.jpg');
+      element._buildAvatarURL({
+        ...createAccountWithId(123),
+        avatars: [
+          {
+            url: 'https://cdn.example.com/s12-p/photo.jpg',
+            height: 12,
+            width: 0,
+          },
+          {
+            url: 'https://cdn.example.com/s16-p/photo.jpg',
+            height: 16,
+            width: 0,
+          },
+          {
+            url: 'https://cdn.example.com/s100-p/photo.jpg',
+            height: 100,
+            width: 0,
+          },
+        ] as AvatarInfo[],
+      }),
+      'https://cdn.example.com/s16-p/photo.jpg'
+    );
     assert.equal(
-        element._buildAvatarURL({
-          _account_id: 123,
-          avatars: [
-            {
-              url: 'https://cdn.example.com/s95-p/photo.jpg',
-              height: 95,
-            },
-          ],
-        }),
-        '/accounts/123/avatar?s=16');
+      element._buildAvatarURL({
+        ...createAccountWithId(123),
+        avatars: [
+          {
+            url: 'https://cdn.example.com/s95-p/photo.jpg',
+            height: 95,
+            width: 0,
+          },
+        ] as AvatarInfo[],
+      }),
+      '/accounts/123/avatar?s=16'
+    );
     assert.equal(element._buildAvatarURL(undefined), '');
   });
 
@@ -114,7 +127,7 @@
 
       element.imageSize = 64;
       element.account = {
-        _account_id: 123,
+        ...createAccountWithId(123),
         avatars: defaultAvatars,
       };
       flush();
@@ -131,14 +144,14 @@
         assert.isFalse(element.hasAttribute('hidden'));
 
         assert.isTrue(
-            element.style.backgroundImage.includes(
-                '/accounts/123/avatar?s=64'));
+          element.style.backgroundImage.includes('/accounts/123/avatar?s=64')
+        );
       });
     });
   });
 
   suite('plugin has avatars', () => {
-    let element;
+    let element: GrAvatar;
 
     setup(() => {
       stub('gr-avatar', '_getConfig').callsFake(() =>
@@ -166,7 +179,7 @@
   });
 
   suite('config not set', () => {
-    let element;
+    let element: GrAvatar;
 
     setup(() => {
       stub('gr-avatar', '_getConfig').callsFake(() => Promise.resolve({}));
@@ -180,7 +193,7 @@
 
       element.imageSize = 64;
       element.account = {
-        _account_id: 123,
+        ...createAccountWithId(123),
         avatars: defaultAvatars,
       };
       // Emulate plugins loaded.
@@ -195,4 +208,3 @@
     });
   });
 });
-
diff --git a/polygerrit-ui/app/elements/shared/gr-formatted-text/gr-formatted-text.ts b/polygerrit-ui/app/elements/shared/gr-formatted-text/gr-formatted-text.ts
index 0193197..ddca5c5 100644
--- a/polygerrit-ui/app/elements/shared/gr-formatted-text/gr-formatted-text.ts
+++ b/polygerrit-ui/app/elements/shared/gr-formatted-text/gr-formatted-text.ts
@@ -183,7 +183,9 @@
         // include pre or all regular lines but stop at next new line
         while (
           this._isPreFormat(lines[nextI]) ||
-          (this._isRegularLine(lines[nextI]) && lines[nextI].length)
+          (this._isRegularLine(lines[nextI]) &&
+            !this._isWhitespaceLine(lines[nextI]) &&
+            lines[nextI].length)
         ) {
           nextI++;
         }
@@ -255,13 +257,17 @@
   }
 
   _isPreFormat(line: string) {
-    return line && /^[ \t]/.test(line);
+    return line && /^[ \t]/.test(line) && !this._isWhitespaceLine(line);
   }
 
   _isList(line: string) {
     return line && /^[-*] /.test(line);
   }
 
+  _isWhitespaceLine(line: string) {
+    return line && /^\s+$/.test(line);
+  }
+
   _makeLinkedText(content = '', isPre?: boolean) {
     const text = document.createElement('gr-linked-text');
     text.config = this.config;
diff --git a/polygerrit-ui/app/elements/shared/gr-formatted-text/gr-formatted-text_test.js b/polygerrit-ui/app/elements/shared/gr-formatted-text/gr-formatted-text_test.js
index 3e05f11..8464af7 100644
--- a/polygerrit-ui/app/elements/shared/gr-formatted-text/gr-formatted-text_test.js
+++ b/polygerrit-ui/app/elements/shared/gr-formatted-text/gr-formatted-text_test.js
@@ -297,6 +297,14 @@
     assertBlock(result, 1, 'paragraph', 'B');
   });
 
+  test('pre format 5', () => {
+    const comment = '  Q\n    <R>\n  S\n \nB';
+    const result = element._computeBlocks(comment);
+    assert.lengthOf(result, 2);
+    assertBlock(result, 0, 'pre', '  Q\n    <R>\n  S');
+    assertBlock(result, 1, 'paragraph', ' \nB');
+  });
+
   test('quote 1', () => {
     const comment = '> I\'m happy\n > with quotes!\n\nSee above.';
     const result = element._computeBlocks(comment);
diff --git a/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text.ts b/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text.ts
index 2812b47..287ed1b 100644
--- a/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text.ts
+++ b/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text.ts
@@ -14,12 +14,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import '../../../styles/shared-styles';
-import {PolymerElement} from '@polymer/polymer/polymer-element';
-import {htmlTemplate} from './gr-linked-text_html';
 import {GrLinkTextParser, LinkTextParserConfig} from './link-text-parser';
 import {GerritNav} from '../../core/gr-navigation/gr-navigation';
-import {customElement, property, observe} from '@polymer/decorators';
+import {GrLitElement} from '../../lit/gr-lit-element';
+import {css, customElement, html, property, query} from 'lit-element';
 
 declare global {
   interface HTMLElementTagNameMap {
@@ -27,17 +25,10 @@
   }
 }
 
-export interface GrLinkedText {
-  $: {
-    output: HTMLSpanElement;
-  };
-}
-
 @customElement('gr-linked-text')
-export class GrLinkedText extends PolymerElement {
-  static get template() {
-    return htmlTemplate;
-  }
+export class GrLinkedText extends GrLitElement {
+  @query('#output')
+  outputElement?: HTMLSpanElement;
 
   @property({type: Boolean})
   removeZeroWidthSpace?: boolean;
@@ -46,61 +37,63 @@
   @property({type: String})
   content: string | null = null;
 
-  @property({type: Boolean, reflectToAttribute: true})
+  @property({type: Boolean, reflect: true})
   pre = false;
 
-  @property({type: Boolean, reflectToAttribute: true})
+  @property({type: Boolean, reflect: true})
   disabled = false;
 
   @property({type: Object})
   config?: LinkTextParserConfig;
 
-  @observe('content')
-  _contentChanged(content: string | null) {
-    // In the case where the config may not be set (perhaps due to the
-    // request for it still being in flight), set the content anyway to
-    // prevent waiting on the config to display the text.
+  static get styles() {
+    return [
+      css`
+        :host {
+          display: block;
+        }
+        :host([pre]) span {
+          white-space: var(--linked-text-white-space, pre-wrap);
+          word-wrap: var(--linked-text-word-wrap, break-word);
+        }
+        :host([disabled]) a {
+          color: inherit;
+          text-decoration: none;
+          pointer-events: none;
+        }
+        a {
+          color: var(--link-color);
+        }
+      `,
+    ];
+  }
+
+  render() {
     if (!this.config) {
       return;
     }
-    this.$.output.textContent = content;
+    return html`<span id="output">${this.content}</span>`;
   }
 
-  /**
-   * Because either the source text or the linkification config has changed,
-   * the content should be re-parsed.
-   *
-   * @param content The raw, un-linkified source string to parse.
-   * @param config The server config specifying commentLink patterns
-   */
-  @observe('content', 'config')
-  _contentOrConfigChanged(
-    content: string | null,
-    config?: LinkTextParserConfig
-  ) {
-    if (!config) {
-      return;
-    }
-
+  updated() {
+    if (!this.outputElement || !this.config) return;
+    this.outputElement.textContent = '';
     // TODO(TS): mapCommentlinks always has value, remove
     if (!GerritNav.mapCommentlinks) return;
-    config = GerritNav.mapCommentlinks(config);
-    const output = this.$.output;
-    output.textContent = '';
+    const config = GerritNav.mapCommentlinks(this.config);
     const parser = new GrLinkTextParser(
       config,
       (text: string | null, href: string | null, fragment?: DocumentFragment) =>
         this._handleParseResult(text, href, fragment),
       this.removeZeroWidthSpace
     );
-    parser.parse(content);
-
+    parser.parse(this.content);
     // Ensure that external links originating from HTML commentlink configs
     // open in a new tab. @see Issue 5567
     // Ensure links to the same host originating from commentlink configs
     // open in the same tab. When target is not set - default is _self
     // @see Issue 4616
-    output.querySelectorAll('a').forEach(anchor => {
+    this.outputElement.querySelectorAll('a').forEach(anchor => {
       if (anchor.hostname === window.location.hostname) {
         anchor.removeAttribute('target');
       } else {
@@ -124,7 +117,8 @@
     href: string | null,
     fragment?: DocumentFragment
   ) {
-    const output = this.$.output;
+    const output = this.outputElement;
+    if (!output) return;
     if (href) {
       const a = document.createElement('a');
       a.setAttribute('href', href);
diff --git a/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_html.ts b/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_html.ts
deleted file mode 100644
index 0d44bc8..0000000
--- a/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_html.ts
+++ /dev/null
@@ -1,38 +0,0 @@
-/**
- * @license
- * Copyright (C) 2020 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.
- */
-import {html} from '@polymer/polymer/lib/utils/html-tag';
-
-export const htmlTemplate = html`
-  <style>
-    :host {
-      display: block;
-    }
-    :host([pre]) span {
-      white-space: var(--linked-text-white-space, pre-wrap);
-      word-wrap: var(--linked-text-word-wrap, break-word);
-    }
-    :host([disabled]) a {
-      color: inherit;
-      text-decoration: none;
-      pointer-events: none;
-    }
-    a {
-      color: var(--link-color);
-    }
-  </style>
-  <span id="output"></span>
-`;
diff --git a/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_test.ts b/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_test.ts
index b2cdba1..c97c168 100644
--- a/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-linked-text/gr-linked-text_test.ts
@@ -85,10 +85,11 @@
     window.CANONICAL_PATH = originalCanonicalPath;
   });
 
-  test('URL pattern was parsed and linked.', () => {
+  test('URL pattern was parsed and linked.', async () => {
     // Regular inline link.
     const url = 'https://bugs.chromium.org/p/gerrit/issues/detail?id=3650';
     element.content = url;
+    await flush();
     const linkEl = queryAndAssert(element, '#output')
       .childNodes[0] as HTMLAnchorElement;
     assert.equal(linkEl.target, '_blank');
@@ -97,9 +98,10 @@
     assert.equal(linkEl.textContent, url);
   });
 
-  test('Bug pattern was parsed and linked', () => {
+  test('Bug pattern was parsed and linked', async () => {
     // "Issue/Bug" pattern.
     element.content = 'Issue 3650';
+    await flush();
 
     let linkEl = queryAndAssert(element, '#output')
       .childNodes[0] as HTMLAnchorElement;
@@ -109,6 +111,7 @@
     assert.equal(linkEl.textContent, 'Issue 3650');
 
     element.content = 'Bug 3650';
+    await flush();
     linkEl = queryAndAssert(element, '#output')
       .childNodes[0] as HTMLAnchorElement;
     assert.equal(linkEl.target, '_blank');
@@ -117,10 +120,10 @@
     assert.equal(linkEl.textContent, 'Bug 3650');
   });
 
-  test('Pattern with same prefix as link was correctly parsed', () => {
+  test('Pattern with same prefix as link was correctly parsed', async () => {
     // Pattern starts with the same prefix (`http`) as the url.
     element.content = 'httpexample 3650';
-
+    await flush();
     assert.equal(queryAndAssert(element, '#output').childNodes.length, 1);
     const linkEl = queryAndAssert(element, '#output')
       .childNodes[0] as HTMLAnchorElement;
@@ -130,12 +133,12 @@
     assert.equal(linkEl.textContent, 'httpexample 3650');
   });
 
-  test('Change-Id pattern was parsed and linked', () => {
+  test('Change-Id pattern was parsed and linked', async () => {
     // "Change-Id:" pattern.
     const changeID = 'I11d6a37f5e9b5df0486f6c922d8836dfa780e03e';
     const prefix = 'Change-Id: ';
     element.content = prefix + changeID;
-
+    await flush();
     const textNode = queryAndAssert(element, '#output').childNodes[0];
     const linkEl = queryAndAssert(element, '#output')
       .childNodes[1] as HTMLAnchorElement;
@@ -147,14 +150,14 @@
     assert.equal(linkEl.textContent, changeID);
   });
 
-  test('Change-Id pattern was parsed and linked with base url', () => {
+  test('Change-Id pattern was parsed and linked with base url', async () => {
     window.CANONICAL_PATH = '/r';
 
     // "Change-Id:" pattern.
     const changeID = 'I11d6a37f5e9b5df0486f6c922d8836dfa780e03e';
     const prefix = 'Change-Id: ';
     element.content = prefix + changeID;
-
+    await flush();
     const textNode = queryAndAssert(element, '#output').childNodes[0];
     const linkEl = queryAndAssert(element, '#output')
       .childNodes[1] as HTMLAnchorElement;
@@ -166,8 +169,9 @@
     assert.equal(linkEl.textContent, changeID);
   });
 
-  test('Multiple matches', () => {
+  test('Multiple matches', async () => {
     element.content = 'Issue 3650\nIssue 3450';
+    await flush();
     const linkEl1 = queryAndAssert(element, '#output')
       .childNodes[0] as HTMLAnchorElement;
     const linkEl2 = queryAndAssert(element, '#output')
@@ -188,7 +192,7 @@
     assert.equal(linkEl2.textContent, 'Issue 3450');
   });
 
-  test('Change-Id pattern parsed before bug pattern', () => {
+  test('Change-Id pattern parsed before bug pattern', async () => {
     // "Change-Id:" pattern.
     const changeID = 'I11d6a37f5e9b5df0486f6c922d8836dfa780e03e';
     const prefix = 'Change-Id: ';
@@ -200,7 +204,7 @@
     const bugUrl = 'https://bugs.chromium.org/p/gerrit/issues/detail?id=3650';
 
     element.content = prefix + changeID + bug;
-
+    await flush();
     const textNode = queryAndAssert(element, '#output').childNodes[0];
     const changeLinkEl = queryAndAssert(element, '#output')
       .childNodes[1] as HTMLAnchorElement;
@@ -218,8 +222,9 @@
     assert.equal(bugLinkEl.textContent, 'Issue 3650');
   });
 
-  test('html field in link config', () => {
+  test('html field in link config', async () => {
     element.content = 'google:do a barrel roll';
+    await flush();
     const linkEl = queryAndAssert(element, '#output')
       .childNodes[0] as HTMLAnchorElement;
     assert.equal(
@@ -229,52 +234,58 @@
     assert.equal(linkEl.textContent, 'do a barrel roll');
   });
 
-  test('removing hash from links', () => {
+  test('removing hash from links', async () => {
     element.content = 'hash:foo';
+    await flush();
     const linkEl = queryAndAssert(element, '#output')
       .childNodes[0] as HTMLAnchorElement;
     assert.isTrue(linkEl.href.endsWith('/awesomesauce'));
     assert.equal(linkEl.textContent, 'foo');
   });
 
-  test('html with base url', () => {
+  test('html with base url', async () => {
     window.CANONICAL_PATH = '/r';
 
     element.content = 'test foo';
+    await flush();
     const linkEl = queryAndAssert(element, '#output')
       .childNodes[0] as HTMLAnchorElement;
     assert.isTrue(linkEl.href.endsWith('/r/awesomesauce'));
     assert.equal(linkEl.textContent, 'foo');
   });
 
-  test('a is not at start', () => {
+  test('a is not at start', async () => {
     window.CANONICAL_PATH = '/r';
 
     element.content = 'a test foo';
+    await flush();
     const linkEl = queryAndAssert(element, '#output')
       .childNodes[1] as HTMLAnchorElement;
     assert.isTrue(linkEl.href.endsWith('/r/awesomesauce'));
     assert.equal(linkEl.textContent, 'foo');
   });
 
-  test('hash html with base url', () => {
+  test('hash html with base url', async () => {
     window.CANONICAL_PATH = '/r';
 
     element.content = 'hash:foo';
+    await flush();
     const linkEl = queryAndAssert(element, '#output')
       .childNodes[0] as HTMLAnchorElement;
     assert.isTrue(linkEl.href.endsWith('/r/awesomesauce'));
     assert.equal(linkEl.textContent, 'foo');
   });
 
-  test('disabled config', () => {
+  test('disabled config', async () => {
     element.content = 'foo:baz';
+    await flush();
     assert.equal(queryAndAssert(element, '#output').innerHTML, 'foo:baz');
   });
 
-  test('R=email labels link correctly', () => {
+  test('R=email labels link correctly', async () => {
     element.removeZeroWidthSpace = true;
     element.content = 'R=\u200Btest@google.com';
+    await flush();
     assert.equal(
       queryAndAssert(element, '#output').textContent,
       'R=test@google.com'
@@ -285,9 +296,10 @@
     );
   });
 
-  test('CC=email labels link correctly', () => {
+  test('CC=email labels link correctly', async () => {
     element.removeZeroWidthSpace = true;
     element.content = 'CC=\u200Btest@google.com';
+    await flush();
     assert.equal(
       queryAndAssert(element, '#output').textContent,
       'CC=test@google.com'
@@ -298,36 +310,42 @@
     );
   });
 
-  test('only {http,https,mailto} protocols are linkified', () => {
+  test('only {http,https,mailto} protocols are linkified', async () => {
     element.content = 'xx mailto:test@google.com yy';
+    await flush();
     let links = queryAndAssert(element, '#output').querySelectorAll('a');
     assert.equal(links.length, 1);
     assert.equal(links[0].getAttribute('href'), 'mailto:test@google.com');
     assert.equal(links[0].innerHTML, 'mailto:test@google.com');
 
     element.content = 'xx http://google.com yy';
+    await flush();
     links = queryAndAssert(element, '#output').querySelectorAll('a');
     assert.equal(links.length, 1);
     assert.equal(links[0].getAttribute('href'), 'http://google.com');
     assert.equal(links[0].innerHTML, 'http://google.com');
 
     element.content = 'xx https://google.com yy';
+    await flush();
     links = queryAndAssert(element, '#output').querySelectorAll('a');
     assert.equal(links.length, 1);
     assert.equal(links[0].getAttribute('href'), 'https://google.com');
     assert.equal(links[0].innerHTML, 'https://google.com');
 
     element.content = 'xx ssh://google.com yy';
+    await flush();
     links = queryAndAssert(element, '#output').querySelectorAll('a');
     assert.equal(links.length, 0);
 
     element.content = 'xx ftp://google.com yy';
+    await flush();
     links = queryAndAssert(element, '#output').querySelectorAll('a');
     assert.equal(links.length, 0);
   });
 
-  test('links without leading whitespace are linkified', () => {
+  test('links without leading whitespace are linkified', async () => {
     element.content = 'xx abcmailto:test@google.com yy';
+    await flush();
     assert.equal(
       queryAndAssert(element, '#output').innerHTML.substr(0, 6),
       'xx abc'
@@ -338,6 +356,7 @@
     assert.equal(links[0].innerHTML, 'mailto:test@google.com');
 
     element.content = 'xx defhttp://google.com yy';
+    await flush();
     assert.equal(
       queryAndAssert(element, '#output').innerHTML.substr(0, 6),
       'xx def'
@@ -348,6 +367,7 @@
     assert.equal(links[0].innerHTML, 'http://google.com');
 
     element.content = 'xx qwehttps://google.com yy';
+    await flush();
     assert.equal(
       queryAndAssert(element, '#output').innerHTML.substr(0, 6),
       'xx qwe'
@@ -359,6 +379,7 @@
 
     // Non-latin character
     element.content = 'xx абвhttps://google.com yy';
+    await flush();
     assert.equal(
       queryAndAssert(element, '#output').innerHTML.substr(0, 6),
       'xx абв'
@@ -369,15 +390,17 @@
     assert.equal(links[0].innerHTML, 'https://google.com');
 
     element.content = 'xx ssh://google.com yy';
+    await flush();
     links = queryAndAssert(element, '#output').querySelectorAll('a');
     assert.equal(links.length, 0);
 
     element.content = 'xx ftp://google.com yy';
+    await flush();
     links = queryAndAssert(element, '#output').querySelectorAll('a');
     assert.equal(links.length, 0);
   });
 
-  test('overlapping links', () => {
+  test('overlapping links', async () => {
     element.config = {
       b1: {
         match: '(B:\\s*)(\\d+)',
@@ -389,7 +412,8 @@
       },
     };
     element.content = '- B: 123, 45';
-    const links = element.root!.querySelectorAll('a');
+    await flush();
+    const links = element.shadowRoot!.querySelectorAll('a');
 
     assert.equal(links.length, 2);
     assert.equal(
@@ -403,12 +427,4 @@
     assert.equal(links[1].href, 'ftp://foo/45');
     assert.equal(links[1].textContent, '45');
   });
-
-  test('_contentOrConfigChanged called with config', () => {
-    const contentStub = sinon.stub(element, '_contentChanged');
-    const contentConfigStub = sinon.stub(element, '_contentOrConfigChanged');
-    element.content = 'some text';
-    assert.isTrue(contentStub.called);
-    assert.isTrue(contentConfigStub.called);
-  });
 });
diff --git a/polygerrit-ui/app/types/common.ts b/polygerrit-ui/app/types/common.ts
index 0f2608e..96c05ee 100644
--- a/polygerrit-ui/app/types/common.ts
+++ b/polygerrit-ui/app/types/common.ts
@@ -43,6 +43,7 @@
   ActionNameToActionInfoMap,
   ApprovalInfo,
   AuthInfo,
+  AvatarInfo,
   BasePatchSetNum,
   BranchName,
   BrandType,
@@ -124,6 +125,7 @@
   ActionNameToActionInfoMap,
   ApprovalInfo,
   AuthInfo,
+  AvatarInfo,
   BasePatchSetNum,
   BranchName,
   BrandType,