Merge changes Iddd04aa3,Ica535e34,I19d7c6f0,I79433c5e,I1566242d

* changes:
  RefPatternMatcher#getUsernames: Remove premature optimization
  RefPatternMatcher#getUsernames: Return ImmutableSet
  IdentifiedUser#getEmailAddresses: Return ImmutableSet
  Add IdentifiedUser#getLoggableName()
  AccountManager#update: Improve logging when username is not changed/set

java/com/google/gerrit/server/IdentifiedUser.java

@@ -301,6 +301,11 @@ public class IdentifiedUser extends CurrentUser {
     return state().getUserName().orElse(null);
   }
 
+  /** @return unique name of the user for logging, never {@code null} */
+  public String getLoggableName() {
+    return getUserName() != null ? getUserName() : "a/" + getAccountId().get();
+  }
+
   public Account getAccount() {
     return state().getAccount();
   }
@@ -320,12 +325,12 @@ public class IdentifiedUser extends CurrentUser {
     return false;
   }
 
-  public Set<String> getEmailAddresses() {
+  public ImmutableSet<String> getEmailAddresses() {
     if (!loadedAllEmails) {
       validEmails.addAll(realm.getEmailAddresses(this));
       loadedAllEmails = true;
     }
-    return validEmails;
+    return ImmutableSet.copyOf(validEmails);
   }
 
   public String getName() {

java/com/google/gerrit/server/account/AccountManager.java

@@ -239,11 +239,14 @@ public class AccountManager {
     }
 
     if (!realm.allowsEdit(AccountFieldName.USER_NAME)
-        && who.getUserName() != null
-        && !Objects.equals(user.getUserName(), Strings.emptyToNull(who.getUserName()))) {
+        && !Strings.isNullOrEmpty(who.getUserName())
+        && !who.getUserName().equals(user.getUserName())) {
+      if (user.getUserName() != null) {
         log.warn(
-          String.format(
-              "Not changing already set username %s to %s", user.getUserName(), who.getUserName()));
+            "Not changing already set username {} to {}", user.getUserName(), who.getUserName());
+      } else {
+        log.warn("Not setting username to {}", who.getUserName());
+      }
     }
 
     if (!accountUpdates.isEmpty()) {

java/com/google/gerrit/server/git/receive/ReceiveCommits.java

@@ -918,7 +918,7 @@ class ReceiveCommits {
                 reject(cmd, "invalid project configuration");
                 logError(
                     "User "
-                        + user.getUserName()
+                        + user.getLoggableName()
                         + " tried to push invalid project configuration "
                         + cmd.getNewId().name()
                         + " for "
@@ -994,7 +994,7 @@ class ReceiveCommits {
               reject(cmd, "invalid project configuration");
               logError(
                   "User "
-                      + user.getUserName()
+                      + user.getLoggableName()
                       + " tried to push invalid project configuration "
                       + cmd.getNewId().name()
                       + " for "

java/com/google/gerrit/server/git/validators/CommitValidators.java

@@ -447,7 +447,7 @@ public class CommitValidators {
         } catch (ConfigInvalidException | IOException e) {
           log.error(
               "User "
-                  + user.getUserName()
+                  + user.getLoggableName()
                   + " tried to push an invalid project configuration "
                   + receiveEvent.command.getNewId().name()
                   + " for project "

java/com/google/gerrit/server/project/RefPatternMatcher.java

@@ -14,11 +14,12 @@
 
 package com.google.gerrit.server.project;
 
+import static com.google.common.collect.ImmutableSet.toImmutableSet;
 import static com.google.gerrit.server.project.RefPattern.isRE;
 
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.Iterables;
+import com.google.common.collect.Streams;
 import com.google.gerrit.common.data.ParameterizedString;
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.RefNames;
@@ -26,7 +27,6 @@ import com.google.gerrit.server.CurrentUser;
 import dk.brics.automaton.Automaton;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.Set;
 import java.util.regex.Pattern;
 
 public abstract class RefPatternMatcher {
@@ -132,15 +132,12 @@ public abstract class RefPatternMatcher {
       return false;
     }
 
-    private Iterable<String> getUsernames(CurrentUser user) {
+    private ImmutableSet<String> getUsernames(CurrentUser user) {
       if (user.isIdentifiedUser()) {
-        Set<String> emails = user.asIdentifiedUser().getEmailAddresses();
-        if (user.getUserName() == null) {
-          return emails;
-        } else if (emails.isEmpty()) {
-          return ImmutableSet.of(user.getUserName());
-        }
-        return Iterables.concat(emails, ImmutableSet.of(user.getUserName()));
+        return Streams.concat(
+                user.asIdentifiedUser().getEmailAddresses().stream(),
+                ImmutableSet.of(user.getUserName()).stream())
+            .collect(toImmutableSet());
       }
       if (user.getUserName() != null) {
         return ImmutableSet.of(user.getUserName());