groups: fix `movewindoworgroup` when moving from group to group (#14086)

* Add test for movewindowgroup

* groups: Fix `movewindoworgroup` moving into group

Fixes `CKeybindManager::moveWindowIntoGroup` to
remove a window from a group before attempting
to add it to another group. Addresses #13843.

But the animation of moving a window from a group
into another group now looks weird: as if the
whole target group is being moved.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/managers/KeybindManager.cpp b/src/managers/KeybindManager.cpp
index 5c233ef5..d7c57baa 100644
--- a/src/managers/KeybindManager.cpp
+++ b/src/managers/KeybindManager.cpp
@@ -2625,6 +2625,8 @@ void CKeybindManager::moveWindowIntoGroup(PHLWINDOW pWindow, PHLWINDOW pWindowIn
         pWindow->m_monitor = pWindowInDirection->m_monitor;
     }
 
+    if (pWindow->m_group)
+        pWindow->m_group->remove(pWindow);
     pWindowInDirection->m_group->add(pWindow);
 
     pWindowInDirection->m_group->setCurrent(pWindow);