fix(wm): add bounds checking in move cmd

This commit ensures that when there is only one container on the target
workspace in a cross-monitor move, meaning that there won't be one
swapped back, we only decrement the focused container index on the
origin workspace if there is a focused container at an index greater
than 0.

fix #209

README.md

@@ -678,4 +678,4 @@ again.
 A [JSON Schema](https://json-schema.org/) of socket messages used to send instructions to `komorebi` can be generated
 with the `komorebic socket-schema` command. The output of this command can be redirected to the clipboard or a file,
 which can be used with services such as [Quicktype](https://app.quicktype.io/) to generate type definitions in different
-programming languages.
+programming languages.

komorebi/src/window_manager.rs

@@ -1047,8 +1047,10 @@ impl WindowManager {
                         let origin_workspace =
                             self.focused_workspace_for_monitor_idx_mut(origin_monitor_idx)?;
 
-                        origin_workspace
-                            .focus_container(origin_workspace.focused_container_idx() - 1);
+                        if origin_workspace.focused_container_idx() != 0 {
+                            origin_workspace
+                                .focus_container(origin_workspace.focused_container_idx() - 1);
+                        }
                     }
                 }