We tried to merge two database and found a problem might be a bug.
To reproduce the issue, please prepare two simple database:
DB1: Topcell(with some patterns and layer=1/0)
DB2: Topcell(with some patterns and layer=1/0)
Open DB1 and then Click File => Import => Other File Into Current
Fill Input File with DB2, and Select Import Mode with Merge option(Merge hierarchy has the same result), click Import.
Two file merged, however the patterns in DB1 disappeared.
Please help to confirm if it's bug or our operation issue, really thanks for your kindly support and hard work.
Klayout version: 0.21.17