From 3179808f1786c6c253757dbf82eafe802134c4bb Mon Sep 17 00:00:00 2001
From: Cody Henthorne <cody@signal.org>
Date: Fri, 2 Oct 2020 11:24:59 -0400
Subject: [PATCH] Cleanup mentions with bad thread ids or ranges, or
 duplicates.

---
 .../securesms/database/MentionUtil.java       |  8 ++--
 .../database/helpers/SQLCipherOpenHelper.java | 39 ++++++++++++++++++-
 2 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/app/src/main/java/org/thoughtcrime/securesms/database/MentionUtil.java b/app/src/main/java/org/thoughtcrime/securesms/database/MentionUtil.java
index b3b9a37bc..d93f25cb1 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/database/MentionUtil.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/database/MentionUtil.java
@@ -16,7 +16,6 @@ import org.thoughtcrime.securesms.database.RecipientDatabase.MentionSetting;
 import org.thoughtcrime.securesms.database.model.Mention;
 import org.thoughtcrime.securesms.database.model.MessageRecord;
 import org.thoughtcrime.securesms.database.model.databaseprotos.BodyRangeList;
-import org.thoughtcrime.securesms.keyvalue.SignalStore;
 import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.recipients.RecipientId;
 import org.whispersystems.signalservice.api.util.UuidUtil;
@@ -24,6 +23,8 @@ import org.whispersystems.signalservice.api.util.UuidUtil;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.SortedSet;
+import java.util.TreeSet;
 
 public final class MentionUtil {
 
@@ -68,14 +69,13 @@ public final class MentionUtil {
       return new UpdatedBodyAndMentions(body, mentions);
     }
 
+    SortedSet<Mention>     sortedMentions  = new TreeSet<>(mentions);
     SpannableStringBuilder updatedBody     = new SpannableStringBuilder();
     List<Mention>          updatedMentions = new ArrayList<>();
 
-    Collections.sort(mentions);
-
     int bodyIndex = 0;
 
-    for (Mention mention : mentions) {
+    for (Mention mention : sortedMentions) {
       updatedBody.append(body.subSequence(bodyIndex, mention.getStart()));
       CharSequence replaceWith    = replacementTextGenerator.apply(mention);
       Mention      updatedMention = new Mention(mention.getRecipientId(), updatedBody.length(), replaceWith.length());
diff --git a/app/src/main/java/org/thoughtcrime/securesms/database/helpers/SQLCipherOpenHelper.java b/app/src/main/java/org/thoughtcrime/securesms/database/helpers/SQLCipherOpenHelper.java
index b544ca339..38095df4e 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/database/helpers/SQLCipherOpenHelper.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/database/helpers/SQLCipherOpenHelper.java
@@ -62,14 +62,17 @@ import org.thoughtcrime.securesms.util.FileUtils;
 import org.thoughtcrime.securesms.util.ServiceUtil;
 import org.thoughtcrime.securesms.util.SqlUtil;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
+import org.thoughtcrime.securesms.util.Triple;
 import org.thoughtcrime.securesms.util.Util;
 
 import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
+import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Set;
 
 public class SQLCipherOpenHelper extends SQLiteOpenHelper {
 
@@ -151,8 +154,9 @@ public class SQLCipherOpenHelper extends SQLiteOpenHelper {
   private static final int THUMBNAIL_CLEANUP                = 74;
   private static final int STICKER_CONTENT_TYPE_CLEANUP     = 75;
   private static final int MENTION_CLEANUP                  = 76;
+  private static final int MENTION_CLEANUP_V2               = 77;
 
-  private static final int    DATABASE_VERSION = 76;
+  private static final int    DATABASE_VERSION = 77;
   private static final String DATABASE_NAME    = "signal.db";
 
   private final Context        context;
@@ -1086,6 +1090,39 @@ public class SQLCipherOpenHelper extends SQLiteOpenHelper {
         }
       }
 
+      if (oldVersion < MENTION_CLEANUP_V2) {
+        String selectMentionIdsWithMismatchingThreadIds = "select mention._id from mention left join mms on mention.message_id = mms._id where mention.thread_id != mms.thread_id";
+        db.delete("mention", "_id in (" + selectMentionIdsWithMismatchingThreadIds + ")", null);
+
+        List<Long>                          idsToDelete   = new LinkedList<>();
+        Set<Triple<Long, Integer, Integer>> mentionTuples = new HashSet<>();
+        try (Cursor cursor = db.rawQuery("select mention.*, mms.body from mention inner join mms on mention.message_id = mms._id order by mention._id desc", null)) {
+          while (cursor != null && cursor.moveToNext()) {
+            long   mentionId   = CursorUtil.requireLong(cursor, "_id");
+            long   messageId   = CursorUtil.requireLong(cursor, "message_id");
+            int    rangeStart  = CursorUtil.requireInt(cursor, "range_start");
+            int    rangeLength = CursorUtil.requireInt(cursor, "range_length");
+            String body        = CursorUtil.requireString(cursor, "body");
+
+            if (body != null && rangeStart < body.length() && body.charAt(rangeStart) != '\uFFFC') {
+              idsToDelete.add(mentionId);
+            } else {
+              Triple<Long, Integer, Integer> tuple = new Triple<>(messageId, rangeStart, rangeLength);
+              if (mentionTuples.contains(tuple)) {
+                idsToDelete.add(mentionId);
+              } else {
+                mentionTuples.add(tuple);
+              }
+            }
+          }
+
+          if (Util.hasItems(idsToDelete)) {
+            String ids = TextUtils.join(",", idsToDelete);
+            db.delete("mention", "_id in (" + ids + ")", null);
+          }
+        }
+      }
+
       db.setTransactionSuccessful();
     } finally {
       db.endTransaction();