Do not move a game that can't be moved; abort before making any changes instead.

However, we handle the exception here and show a warning dialog about this. The user can choose to just set the location without moving or updating anything - they'll have to fix things up themselves.

Should help with #5223

lutris/exceptions.py

@@ -95,6 +95,10 @@ class MissingGameExecutableError(MissingExecutableError):
         self.filename = filename
 
 
+class InvalidGameMoveError(LutrisError):
+    """Raised when a game can't be moved as desired; we may have to just set the location."""
+
+
 class EsyncLimitError(Exception):
     """Raised when the ESYNC limit is not set correctly."""
 

lutris/game.py

@@ -20,7 +20,7 @@ from lutris.database import categories as categories_db
 from lutris.database import games as games_db
 from lutris.database import sql
 from lutris.exception_backstops import watch_game_errors
-from lutris.exceptions import GameConfigError, MissingExecutableError
+from lutris.exceptions import GameConfigError, InvalidGameMoveError, MissingExecutableError
 from lutris.runner_interpreter import export_bash_script, get_launch_parameters
 from lutris.runners import InvalidRunnerError, import_runner
 from lutris.runners.runner import Runner
@@ -960,16 +960,22 @@ class Game(GObject.Object):
         logger.info("Moving %s to %s", self, new_location)
         new_config = ""
         old_location = self.directory
-        if os.path.exists(old_location):
-            game_directory = os.path.basename(old_location)
-            target_directory = os.path.join(new_location, game_directory)
-        else:
-            target_directory = new_location
+        target_directory = self._get_move_target_directory(new_location)
+
+        # Raise errors before actually changing anything!
+        if not old_location:
+            raise InvalidGameMoveError(_("The game has no location currently set, so it can't be moved."))
+
+        if not system.path_exists(old_location):
+            raise InvalidGameMoveError(
+                _("The location '%s' does not exist, perhaps the files have already been moved?") % old_location)
+
+        if new_location.startswith(old_location):
+            raise InvalidGameMoveError(
+                _("Lutris can't move '%s' to a location inside of itself, '%s'.") % (old_location, new_location))
+
         self.directory = target_directory
         self.save()
-        if not old_location:
-            logger.info("Previous location wasn't set. Cannot continue moving")
-            return target_directory
 
         with open(self.config.game_config_path, encoding='utf-8') as config_file:
             for line in config_file.readlines():
@@ -980,12 +986,6 @@ class Game(GObject.Object):
         with open(self.config.game_config_path, "w", encoding='utf-8') as config_file:
             config_file.write(new_config)
 
-        if not system.path_exists(old_location):
-            logger.warning("Location %s doesn't exist, files already moved?", old_location)
-            return target_directory
-        if new_location.startswith(old_location):
-            logger.warning("Can't move %s to one of its children %s", old_location, new_location)
-            return target_directory
         try:
             shutil.move(old_location, new_location)
         except OSError as ex:
@@ -995,6 +995,20 @@ class Game(GObject.Object):
             )
         return target_directory
 
+    def set_location(self, new_location):
+        target_directory = self._get_move_target_directory(new_location)
+        self.directory = target_directory
+        self.save()
+        return target_directory
+
+    def _get_move_target_directory(self, new_location):
+        old_location = self.directory
+        if old_location and os.path.exists(old_location):
+            game_directory = os.path.basename(old_location)
+            return os.path.join(new_location, game_directory)
+
+        return new_location
+
 
 def export_game(slug, dest_dir):
     """Export a full game folder along with some lutris metadata"""

lutris/gui/dialogs/__init__.py

@@ -11,6 +11,7 @@ gi.require_version('Gtk', '3.0')
 from gi.repository import Gdk, GLib, GObject, Gtk
 
 from lutris import api, settings
+from lutris.exceptions import InvalidGameMoveError
 from lutris.gui.widgets.log_text_view import LogTextView
 from lutris.util import datapath
 from lutris.util.jobs import AsyncCall
@@ -522,19 +523,6 @@ class InstallerSourceDialog(ModelessDialog):
         self.show_all()
 
 
-class WarningMessageDialog(Gtk.MessageDialog):
-    def __init__(self, message, secondary_message="", parent=None):
-        super().__init__(type=Gtk.MessageType.WARNING, buttons=Gtk.ButtonsType.OK, parent=parent)
-
-        self.set_default_response(Gtk.ResponseType.OK)
-        self.set_markup("<b>%s</b>" % message)
-        if secondary_message:
-            self.props.secondary_use_markup = True
-            self.props.secondary_text = secondary_message
-        self.run()
-        self.destroy()
-
-
 class MoveDialog(ModelessDialog):
     __gsignals__ = {
         "game-moved": (GObject.SIGNAL_RUN_FIRST, None, ()),
@@ -564,7 +552,7 @@ class MoveDialog(ModelessDialog):
         GLib.source_remove(self.progress_source_id)
 
     def move(self):
-        AsyncCall(self._move_game, self.on_game_moved)
+        AsyncCall(self._move_game, self._move_game_cb)
 
     def show_progress(self):
         self.progress.pulse()
@@ -573,6 +561,20 @@ class MoveDialog(ModelessDialog):
     def _move_game(self):
         self.new_directory = self.game.move(self.destination)
 
+    def _move_game_cb(self, _result, error):
+        if error and isinstance(error, InvalidGameMoveError):
+            secondary = _("Do you want to change the game location anyway? No files can be moved, "
+                          "and the game configuration may need to be adjusted.")
+            dlg = WarningDialog(str(error), secondary=secondary, parent=self)
+            if dlg.result == Gtk.ResponseType.OK:
+                self.new_directory = self.game.set_location(self.destination)
+                self.on_game_moved(None, None)
+            else:
+                self.destroy()
+            return
+
+        self.on_game_moved(_result, error)
+
     def on_game_moved(self, _result, error):
         if error:
             ErrorDialog(error, parent=self)