Nasty hack to retain threads in MessageListFragment when polling

src/com/fsck/k9/activity/MessageInfoHolder.java

@@ -24,6 +24,7 @@ public class MessageInfoHolder {
     public boolean selected;
     public String account;
     public String uri;
+    public int threadCount;
 
     // Empty constructor for comparison
     public MessageInfoHolder() {

src/com/fsck/k9/fragment/MessageListFragment.java

@@ -687,7 +687,7 @@ public class MessageListFragment extends SherlockFragment implements OnItemClick
         final MessageInfoHolder message = (MessageInfoHolder) parent.getItemAtPosition(position);
         if (mSelectedCount > 0) {
             toggleMessageSelect(message);
-        } else if (((LocalMessage) message.message).getThreadCount() > 1) {
+        } else if (message.threadCount > 1) {
             Folder folder = message.message.getFolder();
             long rootId = ((LocalMessage) message.message).getRootId();
             mFragmentListener.showThread(folder.getAccount(), folder.getName(), rootId);
@@ -1767,7 +1767,36 @@ public class MessageListFragment extends SherlockFragment implements OnItemClick
                             FolderInfoHolder folderInfoHolder = new FolderInfoHolder(
                                     getActivity(), messageFolder, messageAccount);
                             messageHelper.populate(m, message, folderInfoHolder, messageAccount);
-                            messagesToAdd.add(m);
+
+                            if (verifyAgainstSearch) {
+                                LocalMessage localMessage = (LocalMessage) message;
+
+                                if (mThreadId != -1) {
+                                    if (localMessage.getRootId() == mThreadId ||
+                                            localMessage.getId() == mThreadId) {
+                                        messagesToAdd.add(m);
+                                    }
+                                } else if (mThreadViewEnabled) {
+                                    long threadId = localMessage.getRootId();
+                                    if (threadId == -1) {
+                                        threadId = localMessage.getId();
+                                    }
+
+                                    MessageInfoHolder threadPlaceHolder = getThread(threadId);
+                                    if (threadPlaceHolder == null) {
+                                        messagesToAdd.add(m);
+                                    } else if (m.compareDate.after(threadPlaceHolder.compareDate)) {
+                                        messagesToRemove.add(threadPlaceHolder);
+                                        messagesToAdd.add(m);
+                                    } else {
+                                        threadPlaceHolder.threadCount = m.threadCount;
+                                    }
+                                } else {
+                                    messagesToAdd.add(m);
+                                }
+                            } else {
+                                messagesToAdd.add(m);
+                            }
                         } else {
                             if (mQueryString != null) {
                                 if (verifyAgainstSearch) {
@@ -1876,6 +1905,17 @@ public class MessageListFragment extends SherlockFragment implements OnItemClick
             return null;
         }
 
+        private MessageInfoHolder getThread(long threadId) {
+            for (MessageInfoHolder holder : mMessages) {
+                LocalMessage localMessage = (LocalMessage) holder.message;
+                if (localMessage.getId() == threadId || localMessage.getRootId() == threadId) {
+                    return holder;
+                }
+            }
+
+            return null;
+        }
+
         public FolderInfoHolder getFolder(String folder, Account account) {
             LocalFolder local_folder = null;
             try {
@@ -2056,7 +2096,7 @@ public class MessageListFragment extends SherlockFragment implements OnItemClick
                 subject = message.message.getSubject();
             }
 
-            int threadCount = ((LocalMessage) message.message).getThreadCount();
+            int threadCount = message.threadCount;
             if (threadCount > 1) {
                 holder.threadCount.setText(Integer.toString(threadCount));
                 holder.threadCount.setVisibility(View.VISIBLE);

src/com/fsck/k9/helper/MessageHelper.java

@@ -17,6 +17,7 @@ import com.fsck.k9.mail.Flag;
 import com.fsck.k9.mail.Message;
 import com.fsck.k9.mail.MessagingException;
 import com.fsck.k9.mail.Message.RecipientType;
+import com.fsck.k9.mail.store.LocalStore.LocalMessage;
 import com.fsck.k9.helper.DateFormatter;
 
 public class MessageHelper {
@@ -86,6 +87,8 @@ public class MessageHelper {
             target.account = account.getUuid();
             target.uri = "email://messages/" + account.getAccountNumber() + "/" + message.getFolder().getName() + "/" + message.getUid();
 
+            target.threadCount = ((LocalMessage) message).getThreadCount();
+
         } catch (MessagingException me) {
             Log.w(K9.LOG_TAG, "Unable to load message info", me);
         }

src/com/fsck/k9/mail/store/LocalStore.java

@@ -93,6 +93,10 @@ public class LocalStore extends Store implements Serializable {
         "subject, sender_list, date, uid, flags, id, to_list, cc_list, "
         + "bcc_list, reply_to_list, attachment_count, internal_date, message_id, folder_id, preview, thread_root, thread_parent, empty ";
 
+    static private String GET_MESSAGES_COLS_PREFIX =
+            "m.subject, m.sender_list, m.date, m.uid, m.flags, m.id, m.to_list, m.cc_list, " +
+            "m.bcc_list, m.reply_to_list, m.attachment_count, m.internal_date, m.message_id, " +
+            "m.folder_id, m.preview, m.thread_root, m.thread_parent, m.empty ";
 
     static private String GET_FOLDER_COLS = "id, name, unread_count, visible_limit, last_updated, status, push_state, last_pushed, flagged_count, integrate, top_group, poll_class, push_class, display_class";
 
@@ -1891,13 +1895,23 @@ public class LocalStore extends Store implements Serializable {
 
                             try {
                                 cursor = db.rawQuery(
-                                             "SELECT "
+                                        "SELECT " +
-                                             + GET_MESSAGES_COLS
+                                        GET_MESSAGES_COLS_PREFIX + ", COUNT(c.id) " +
-                                             + "FROM messages WHERE uid = ? AND folder_id = ?",
+                                        "FROM messages m LEFT JOIN messages c " +
+                                        "ON (" +
+                                            "(" +
+                                                "m.thread_root IN (c.thread_root, c.id)" +
+                                                " OR " +
+                                                "(m.thread_root IS NULL AND m.id IN (c.thread_root, c.id))" +
+                                            ") AND c.empty != 1) " +
+                                        "WHERE m.uid = ? AND m.folder_id = ?",
                                              new String[] {
                                                  message.getUid(), Long.toString(mFolderId)
                                              });
-                                if (!cursor.moveToNext()) {
+
+                                // Note: Because of the COUNT(c.id) we will always get one result
+                                //       row even if nothing was found. So we check if 'id' is NULL
+                                if (!cursor.moveToNext() || cursor.isNull(0)) {
                                     return null;
                                 }
                                 message.populateFromGetMessageCursor(cursor);