Allow placing widget in hotseat (#3930)

src/com/android/launcher3/Launcher.java

@@ -991,7 +991,7 @@ public class Launcher extends StatefulActivity<LauncherState>
                             presenterPos.cellX, presenterPos.cellY, newScreenId, CONTAINER_DESKTOP).screenId;
                 }
                 final CellLayout dropLayout = mWorkspace.getScreenWithId(presenterPos.screenId);
-
+                if (dropLayout == null) return;
                 dropLayout.setDropPending(true);
                 final Runnable onComplete = new Runnable() {
                     @Override

src/com/android/launcher3/Workspace.java

@@ -494,6 +494,7 @@ public class Workspace<T extends View & PageIndicator> extends PagedView<T>
 
     public Rect estimateItemPosition(CellLayout cl, int hCell, int vCell, int hSpan, int vSpan) {
         Rect r = new Rect();
+        if (cl == null) return r;
         cl.cellToRect(hCell, vCell, hSpan, vSpan, r);
         return r;
     }
@@ -2709,8 +2710,7 @@ public class Workspace<T extends View & PageIndicator> extends PagedView<T>
 
     private boolean shouldUseHotseatAsDropLayout(DragObject dragObject) {
         if (mLauncher.getHotseat() == null
-                || mLauncher.getHotseat().getShortcutsAndWidgets() == null
-                || isDragWidget(dragObject)) {
+                || mLauncher.getHotseat().getShortcutsAndWidgets() == null) {
             return false;
         }
         View hotseatShortcuts = mLauncher.getHotseat().getShortcutsAndWidgets();