When -storetype is not provided, keytool's internal flag hasStoretypeOption is false and it will probe the keystore file to detect its store type.

For the -importkeystore command, there are both a source keystore and a destination keystore, as well as the -srcstoretype and -deststoretype options. However, keytool still only uses a single flag for both. The result is that when -deststoretype is provided but -srcstoretype is not provided, it does not probe for the storetype of the source keystore and always uses the default storetype.