Fix duplicate items after grid migration

src/com/android/launcher3/LauncherProvider.java

@@ -171,8 +171,11 @@ public class LauncherProvider extends ContentProvider {
 
         final DatabaseHelper helper = src.get();
         mOpenHelper = dst.get();
+        SQLiteDatabase toDb = mOpenHelper.getWritableDatabase();
         copyTable(helper.getReadableDatabase(), Favorites.TABLE_NAME,
-                mOpenHelper.getWritableDatabase(), targetTableName, getContext());
+                toDb, targetTableName, getContext());
+        // remove old items in the db
+        copyTable(toDb, targetTableName, toDb, Favorites.TABLE_NAME, getContext());
         helper.close();
         return true;
     }

src/com/android/launcher3/model/GridSizeMigrationTaskV2.java

@@ -91,8 +91,24 @@ public class GridSizeMigrationTaskV2 {
         mSrcReader = srcReader;
         mDestReader = destReader;
 
-        mHotseatItems = destReader.loadHotseatEntries();
-        mWorkspaceItems = destReader.loadAllWorkspaceEntries();
+        List<DbEntry> hotseatItems = destReader.loadHotseatEntries();
+        List<DbEntry> workspaceItems = destReader.loadAllWorkspaceEntries();
+
+        // only add items in the target size. other items are considered lost
+        mHotseatItems = new ArrayList<>();
+        for (int i = 0; i < hotseatItems.size(); i++) {
+            DbEntry item = hotseatItems.get(i);
+            if (item.cellX < destHotseatSize) {
+                mHotseatItems.add(item);
+            }
+        }
+        mWorkspaceItems = new ArrayList<>();
+        for (int i = 0; i < workspaceItems.size(); i++) {
+            DbEntry item = workspaceItems.get(i);
+            if (item.cellX < targetSize.x && item.cellY < targetSize.y) {
+                mWorkspaceItems.add(item);
+            }
+        }
 
         mHotseatDiff = calcDiff(mSrcReader.loadHotseatEntries(), mHotseatItems);
         mWorkspaceDiff = calcDiff(mSrcReader.loadAllWorkspaceEntries(), mWorkspaceItems);