Prevent leading and trailing whitespace in group names.

app/src/main/java/org/thoughtcrime/securesms/profiles/edit/EditProfileViewModel.java

@@ -13,7 +13,7 @@ import androidx.lifecycle.ViewModelProvider;
 import org.thoughtcrime.securesms.groups.GroupId;
 import org.thoughtcrime.securesms.profiles.ProfileName;
 import org.thoughtcrime.securesms.util.StringUtil;
-import org.thoughtcrime.securesms.util.livedata.LiveDataPair;
+import org.thoughtcrime.securesms.util.livedata.LiveDataUtil;
 import org.whispersystems.libsignal.util.guava.Optional;
 
 import java.util.Objects;
@@ -22,19 +22,20 @@ class EditProfileViewModel extends ViewModel {
 
   private final MutableLiveData<String>           givenName           = new MutableLiveData<>();
   private final MutableLiveData<String>           familyName          = new MutableLiveData<>();
-  private final LiveData<ProfileName>             internalProfileName = Transformations.map(new LiveDataPair<>(givenName, familyName),
+  private final LiveData<String>                  trimmedGivenName    = Transformations.map(givenName, StringUtil::trimToVisualBounds);
-                                                                                            pair -> ProfileName.fromParts(pair.first(), pair.second()));
+  private final LiveData<String>                  trimmedFamilyName   = Transformations.map(familyName, StringUtil::trimToVisualBounds);
+  private final LiveData<ProfileName>             internalProfileName = LiveDataUtil.combineLatest(trimmedGivenName, trimmedFamilyName, ProfileName::fromParts);
   private final MutableLiveData<byte[]>           internalAvatar      = new MutableLiveData<>();
   private final MutableLiveData<byte[]>           originalAvatar      = new MutableLiveData<>();
   private final MutableLiveData<Optional<String>> internalUsername    = new MutableLiveData<>();
   private final MutableLiveData<String>           originalDisplayName = new MutableLiveData<>();
-  private final LiveData<Boolean>                 isFormValid         = Transformations.map(givenName, name -> !StringUtil.isVisuallyEmpty(name));
+  private final LiveData<Boolean>                 isFormValid         = Transformations.map(trimmedGivenName, s -> s.length() > 0);
   private final EditProfileRepository             repository;
   private final GroupId                           groupId;
 
   private EditProfileViewModel(@NonNull EditProfileRepository repository, boolean hasInstanceState, @Nullable GroupId groupId) {
-    this.repository  = repository;
+    this.repository = repository;
-    this.groupId     = groupId;
+    this.groupId    = groupId;
 
     repository.getCurrentUsername(internalUsername::postValue);
 
@@ -141,9 +142,8 @@ class EditProfileViewModel extends ViewModel {
       this.groupId          = groupId;
     }
 
-    @NonNull
     @Override
-    public <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
+    public @NonNull <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
       //noinspection unchecked
       return (T) new EditProfileViewModel(repository, hasInstanceState, groupId);
     }

app/src/main/java/org/thoughtcrime/securesms/util/StringUtil.java

@@ -45,13 +45,44 @@ public final class StringUtil {
       return true;
     }
 
-    for (int i = 0; i < value.length(); i++) {
+    return indexOfFirstNonEmptyChar(value) == -1;
+  }
+
+  /**
+   * @return String without any leading or trailing whitespace.
+   *         Accounts for various unicode whitespace characters.
+   */
+  public static String trimToVisualBounds(@NonNull String value) {
+    int start = indexOfFirstNonEmptyChar(value);
+
+    if (start == -1) {
+      return "";
+    }
+
+    int end = indexOfLastNonEmptyChar(value);
+
+    return value.substring(start, end + 1);
+  }
+
+  private static int indexOfFirstNonEmptyChar(@NonNull String value) {
+    int length = value.length();
+
+    for (int i = 0; i < length; i++) {
       if (!isVisuallyEmpty(value.charAt(i))) {
-        return false;
+        return i;
       }
     }
 
-    return true;
+    return -1;
+  }
+
+  private static int indexOfLastNonEmptyChar(@NonNull String value) {
+    for (int i = value.length() - 1; i >= 0; i--) {
+      if (!isVisuallyEmpty(value.charAt(i))) {
+        return i;
+      }
+    }
+    return -1;
   }
 
   /**

app/src/test/java/org/thoughtcrime/securesms/util/StringUtilTest_whitespace_handling.java

@@ -0,0 +1,54 @@
+package org.thoughtcrime.securesms.util;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(Parameterized.class)
+public final class StringUtilTest_whitespace_handling {
+
+  private final String  input;
+  private final String  expectedTrimmed;
+  private final boolean isVisuallyEmpty;
+
+  @Parameterized.Parameters
+  public static Collection<Object[]> data() {
+    return Arrays.asList(new Object[][]{
+
+      { "", "", true },
+      { " ", "", true },
+      { "A", "A", false },
+      { " B", "B", false },
+      { "C ", "C", false },
+
+      /* Unicode whitespace */
+      { "\u200E", "", true },
+      { "\u200F", "", true },
+      { "\u2007", "", true },
+      { "\u2007\u200FA\tB\u200EC\u200E\u200F", "A\tB\u200EC", false },
+
+    });
+  }
+
+  public StringUtilTest_whitespace_handling(String input, String expectedTrimmed, boolean isVisuallyEmpty) {
+    this.input           = input;
+    this.expectedTrimmed = expectedTrimmed;
+    this.isVisuallyEmpty = isVisuallyEmpty;
+  }
+
+  @Test
+  public void isVisuallyEmpty() {
+    assertEquals(isVisuallyEmpty, StringUtil.isVisuallyEmpty(input));
+  }
+
+  @Test
+  public void trim() {
+    assertEquals(expectedTrimmed, StringUtil.trimToVisualBounds(input));
+  }
+
+}

libsignal/service/src/main/java/org/whispersystems/signalservice/api/groupsv2/GroupsV2Operations.java

@@ -545,7 +545,7 @@ public final class GroupsV2Operations {
     }
 
     private String decryptTitle(ByteString cipherText) {
-      return decryptBlob(cipherText).getTitle();
+      return decryptBlob(cipherText).getTitle().trim();
     }
 
     private int decryptDisappearingMessagesTimer(ByteString encryptedTimerMessage) {