seatmgr: fix missing nullcheck in updateActiveKeyboardData

sometimes we may set a keyboard that's about-to-be-deleted, we might as well check for that

additionally avoid setting null keyboards altogether

src/managers/SeatManager.cpp

@@ -94,7 +94,7 @@ void CSeatManager::setKeyboard(SP<IKeyboard> KEEB) {
 }
 
 void CSeatManager::updateActiveKeyboardData() {
-    if (keyboard)
+    if (keyboard && keyboard->wlr())
         PROTO::seat->updateRepeatInfo(keyboard->wlr()->repeat_info.rate, keyboard->wlr()->repeat_info.delay);
     PROTO::seat->updateKeymap();
 }

src/managers/input/InputManager.cpp

@@ -1226,12 +1226,20 @@ void CInputManager::destroyKeyboard(SP<IKeyboard> pKeyboard) {
     std::erase_if(m_vKeyboards, [pKeyboard](const auto& other) { return other == pKeyboard; });
 
     if (m_vKeyboards.size() > 0) {
-        const auto PNEWKEYBOARD = m_vKeyboards.back();
-        g_pSeatManager->setKeyboard(PNEWKEYBOARD);
-        PNEWKEYBOARD->active = true;
-    } else {
+        bool found = false;
+        for (auto& k : m_vKeyboards | std::views::reverse) {
+            if (!k->wlr())
+                continue;
+
+            g_pSeatManager->setKeyboard(k);
+            found = true;
+            break;
+        }
+
+        if (!found)
+            g_pSeatManager->setKeyboard(nullptr);
+    } else
         g_pSeatManager->setKeyboard(nullptr);
-    }
 
     removeFromHIDs(pKeyboard);
 }