Added the ability to completely wipe the localy cached messages of a syncced folder.

res/menu/folder_context.xml

@@ -24,6 +24,10 @@
         android:id="@+id/folder_settings"
 		android:title="@string/folder_settings_action"
     />
+    <item
+        android:id="@+id/clear_local_folder"
+        android:title="@string/clear_local_folder_action"
+    />
     <item
         android:id="@+id/expunge"
         android:title="@string/expunge_action"

res/values/strings.xml

@@ -114,6 +114,7 @@
     <string name="dump_settings_action">Dump settings</string>
     <string name="empty_trash_action">Empty Trash</string>
     <string name="expunge_action">Expunge</string>
+    <string name="clear_local_folder_action">Clear local messages</string>
     <string name="set_sort_action">Choose sort</string>
     <string name="reverse_sort_action">Reverse sort</string>
     <string name="about_action">About</string>

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

@@ -31,6 +31,7 @@ import com.fsck.k9.helper.power.TracingPowerManager.TracingWakeLock;
 import com.fsck.k9.mail.Flag;
 import com.fsck.k9.mail.Folder;
 import com.fsck.k9.mail.Message;
+import com.fsck.k9.mail.store.LocalStore.LocalFolder;
 import com.fsck.k9.mail.MessagingException;
 import com.fsck.k9.service.MailService;
 import java.util.ArrayList;
@@ -538,6 +539,43 @@ public class FolderList extends K9ListActivity
         MessagingController.getInstance(getApplication()).expunge(account, folderName, null);
     }
 
+
+    private void onClearFolder(Account account, String folderName)
+    {
+        // There has to be a cheaper way to get at the localFolder object than this
+        LocalFolder localFolder = null;
+        try
+        {
+            if (account == null || folderName == null || !account.isAvailable(FolderList.this))
+            {
+                Log.i(K9.LOG_TAG, "not clear folder of unavailable account");
+                return;
+            }
+            localFolder = account.getLocalStore().getFolder(folderName);
+            localFolder.open(Folder.OpenMode.READ_WRITE);
+            if (localFolder != null)
+            {
+                localFolder.clearAllMessages();
+            }
+        }
+        catch (Exception e)
+        {
+            Log.e(K9.LOG_TAG, "Exception while clearing folder", e);
+        }
+        finally
+        {
+            if (localFolder != null)
+            {
+                localFolder.close();
+            }
+        }
+
+    }
+
+
+
+
+
     private void sendMail(Account account)
     {
         MessagingController.getInstance(getApplication()).sendPendingMessages(account, mAdapter.mListener);
@@ -675,6 +713,10 @@ public class FolderList extends K9ListActivity
                 onExpunge(mAccount, folder.name);
 
                 break;
+
+            case R.id.clear_local_folder:
+                onClearFolder(mAccount,folder.name);
+                break;
         }
 
         return super.onContextItemSelected(item);

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

@@ -3475,6 +3475,22 @@ public class LocalStore extends Store implements Serializable, LocalStoreMigrati
         }
 
 
+
+        public void clearAllMessages() throws MessagingException
+        {
+            final String where = "folder_id = ?";
+            final String[] params = new String[]
+            {
+                Long.toString(mFolderId)
+            };
+
+
+            clearMessagesWhere(where, params);
+            setPushState(null);
+            setLastPush(0);
+            setLastChecked(0);
+        }
+
         private void resetUnreadAndFlaggedCounts()
         {
             try