Fix improper deletion of stickers when restored from backup.

app/src/main/java/org/thoughtcrime/securesms/backup/FullBackupImporter.java

@@ -156,7 +156,7 @@ public class FullBackupImporter extends FullBackupBase {
   private static void processSticker(@NonNull Context context, @NonNull AttachmentSecret attachmentSecret, @NonNull SQLiteDatabase db, @NonNull Sticker sticker, BackupRecordInputStream inputStream)
       throws IOException
   {
-    File stickerDirectory = context.getDir(AttachmentDatabase.DIRECTORY, Context.MODE_PRIVATE);
+    File stickerDirectory = context.getDir(StickerDatabase.DIRECTORY, Context.MODE_PRIVATE);
     File dataFile         = File.createTempFile("sticker", ".mms", stickerDirectory);
 
     Pair<byte[], OutputStream> output = ModernEncryptingPartOutputStream.createFor(attachmentSecret, dataFile, false);

app/src/main/java/org/thoughtcrime/securesms/database/AttachmentDatabase.java

@@ -509,6 +509,8 @@ public class AttachmentDatabase extends Database {
       }
     }
 
+    filesInDb.addAll(DatabaseFactory.getStickerDatabase(context).getAllStickerFiles());
+
     Set<String> onDiskButNotInDatabase = SetUtil.difference(filesOnDisk, filesInDb);
 
     for (String filePath : onDiskButNotInDatabase) {

app/src/main/java/org/thoughtcrime/securesms/database/StickerDatabase.java

@@ -3,12 +3,12 @@ package org.thoughtcrime.securesms.database;
 import android.content.ContentValues;
 import android.content.Context;
 import android.database.Cursor;
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-
 import android.text.TextUtils;
 import android.util.Pair;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import net.sqlcipher.database.SQLiteDatabase;
 
 import org.greenrobot.eventbus.EventBus;
@@ -23,6 +23,7 @@ import org.thoughtcrime.securesms.logging.Log;
 import org.thoughtcrime.securesms.mms.DecryptableStreamUriLoader.DecryptableUri;
 import org.thoughtcrime.securesms.stickers.BlessedPacks;
 import org.thoughtcrime.securesms.stickers.StickerPackInstallEvent;
+import org.thoughtcrime.securesms.util.CursorUtil;
 import org.thoughtcrime.securesms.util.Util;
 
 import java.io.Closeable;
@@ -30,9 +31,9 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.io.UnsupportedEncodingException;
-import java.net.URLEncoder;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 public class StickerDatabase extends Database {
 
@@ -77,7 +78,7 @@ public class StickerDatabase extends Database {
       "CREATE INDEX IF NOT EXISTS sticker_sticker_id_index ON " + TABLE_NAME + " (" + STICKER_ID + ");"
   };
 
-  private static final String DIRECTORY = "stickers";
+  public static final String DIRECTORY = "stickers";
 
   private final AttachmentSecret attachmentSecret;
 
@@ -190,6 +191,19 @@ public class StickerDatabase extends Database {
     return cursor;
   }
 
+  public @NonNull Set<String> getAllStickerFiles() {
+    SQLiteDatabase db        = databaseHelper.getReadableDatabase();
+
+    Set<String> files = new HashSet<>();
+    try (Cursor cursor = db.query(TABLE_NAME, new String[] { FILE_PATH }, null, null, null, null, null)) {
+      while (cursor != null && cursor.moveToNext()) {
+        files.add(CursorUtil.requireString(cursor, FILE_PATH));
+      }
+    }
+
+    return files;
+  }
+
   public @Nullable InputStream getStickerStream(long rowId) throws IOException {
     String   selection = _ID + " = ?";
     String[] args      = new String[] { String.valueOf(rowId) };

app/src/main/java/org/thoughtcrime/securesms/database/ThreadDatabase.java

@@ -296,6 +296,10 @@ public class ThreadDatabase extends Database {
   }
 
   public void trimThread(long threadId, int length, long trimBeforeDate) {
+    if (length == NO_TRIM_MESSAGE_COUNT_SET && trimBeforeDate == NO_TRIM_BEFORE_DATE_SET) {
+      return;
+    }
+
     SQLiteDatabase       db                   = databaseHelper.getWritableDatabase();
     AttachmentDatabase   attachmentDatabase   = DatabaseFactory.getAttachmentDatabase(context);
     GroupReceiptDatabase groupReceiptDatabase = DatabaseFactory.getGroupReceiptDatabase(context);