UID EXPUNGE for folders

app/src/main/java/eu/faircode/email/Core.java

@@ -2692,7 +2692,33 @@ class Core {
 
     private static void onExpungeFolder(Context context, JSONArray jargs, EntityFolder folder, IMAPFolder ifolder) throws MessagingException {
         Log.i(folder.name + " expunge");
-        ifolder.expunge();
+
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        boolean uid_expunge = prefs.getBoolean("uid_expunge", false);
+        int chunk_size = prefs.getInt("chunk_size", DEFAULT_CHUNK_SIZE);
+
+        if (uid_expunge)
+            uid_expunge = MessageHelper.hasCapability(ifolder, "UIDPLUS");
+
+        if (uid_expunge) {
+            DB db = DB.getInstance(context);
+
+            List<Long> uids = db.message().getDeletedUids(folder.id);
+            if (uids == null || uids.size() == 0)
+                return;
+
+            Log.i(ifolder.getName() + " expunging " + TextUtils.join(",", uids));
+            ifolder.doCommand(new IMAPFolder.ProtocolCommand() {
+                @Override
+                public Object doCommand(IMAPProtocol protocol) throws ProtocolException {
+                    for (List<Long> list : Helper.chunkList(uids, chunk_size))
+                        protocol.uidexpunge(UIDSet.createUIDSets(Helper.toLongArray(list)));
+                    return null;
+                }
+            });
+            Log.i(ifolder.getName() + " expunged " + TextUtils.join(",", uids));
+        } else
+            ifolder.expunge();
     }
 
     private static void onPurgeFolder(Context context, EntityFolder folder) {

app/src/main/java/eu/faircode/email/DaoMessage.java

@@ -623,6 +623,12 @@ public interface DaoMessage {
             " AND NOT content")
     List<EntityMessage> getMessagesWithoutContent(long folder, Long received);
 
+    @Query("SELECT uid FROM message" +
+            " WHERE folder = :folder" +
+            " AND ui_deleted" +
+            " AND NOT uid IS NULL")
+    List<Long> getDeletedUids(long folder);
+
     @Query("SELECT uid FROM message" +
             " WHERE folder = :folder" +
             " AND NOT ui_busy IS NULL" +

app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java

@@ -1043,7 +1043,6 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
             @Override
             public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
                 prefs.edit().putBoolean("perform_expunge", checked).apply();
-                swUidExpunge.setEnabled(checked);
                 ServiceSynchronize.reload(compoundButton.getContext(), null, true, "perform_expunge");
             }
         });
@@ -1713,7 +1712,6 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         swUid.setChecked(prefs.getBoolean("uid_command", false));
         swExpunge.setChecked(prefs.getBoolean("perform_expunge", true));
         swUidExpunge.setChecked(prefs.getBoolean("uid_expunge", false));
-        swUidExpunge.setEnabled(swExpunge.isChecked());
         swAuthPlain.setChecked(prefs.getBoolean("auth_plain", true));
         swAuthLogin.setChecked(prefs.getBoolean("auth_login", true));
         swAuthNtlm.setChecked(prefs.getBoolean("auth_ntlm", true));

app/src/main/res/layout/fragment_options_misc.xml

@@ -997,7 +997,6 @@
                     android:id="@+id/swUidExpunge"
                     android:layout_width="0dp"
                     android:layout_height="wrap_content"
-                    android:layout_marginStart="12dp"
                     android:layout_marginTop="12dp"
                     android:text="@string/title_advanced_uid_expunge"
                     app:layout_constraintEnd_toEndOf="parent"