Attempting to drop a database which was created with dolt_clone fails.

[reltuk]

Running the following script:

mkdir droptest
cd droptest
dolt init
dolt remote add pushed 'file://../pushed'
dolt push pushed main:main
dolt sql -q 'call dolt_clone("file://../pushed", "cloned"); drop database cloned;'

Results in:

error on line 1 for query  drop database cloned: database not found: cloned
WARN[0000] journal writer has already been closed (/Users/aaronson/dolttest/droptest/cloned/.dolt/noms/vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv) 
panic: Close() called and reduced ref count to < 0.

goroutine 1 [running]:
github.com/dolthub/dolt/go/store/nbs.onHeapTableIndex.Close({{0x14000b4c640, 0x18, 0x4c}, {0x14000af0210, 0x8, 0x8}, {0x14000b4c658, 0x8, 0x34}, {0x14000b4c660, ...}, ...})
	/Users/aaronson/src/dolt/go/store/nbs/table_index.go:528 +0xe0
github.com/dolthub/dolt/go/store/nbs.tableReader.close({{0x14000af0220, 0x2, 0x2}, {0x107434390, 0x140008d9130}, {0x1073a81b0, 0x140000a24a0}, 0x1000})
	/Users/aaronson/src/dolt/go/store/nbs/table_reader.go:691 +0x48
github.com/dolthub/dolt/go/store/nbs.tableSet.close({0x0, 0x14000aa3c20, {0x1073b84a8, 0x1400019f140}, {0x1073a0fa0, 0x14000122340}, 0x140000b84e0})
	/Users/aaronson/src/dolt/go/store/nbs/table_set.go:277 +0x100
github.com/dolthub/dolt/go/store/nbs.(*NomsBlockStore).Close(0x1400019c160)
	/Users/aaronson/src/dolt/go/store/nbs/store.go:1307 +0x9c
github.com/dolthub/dolt/go/store/nbs.(*GenerationalNBS).Close(0x14000e6e190)
	/Users/aaronson/src/dolt/go/store/nbs/generational_chunk_store.go:229 +0x40
github.com/dolthub/dolt/go/store/types.(*ValueStore).Close(...)
	/Users/aaronson/src/dolt/go/store/types/value_store.go:799
github.com/dolthub/dolt/go/store/datas.(*database).Close(0x14000a35730?)
	/Users/aaronson/src/dolt/go/store/datas/database_common.go:267 +0x2c
github.com/dolthub/dolt/go/libraries/doltcore/dbfactory.CloseAllLocalDatabases()
	/Users/aaronson/src/dolt/go/libraries/doltcore/dbfactory/file.go:73 +0x138
main.runMain()
	/Users/aaronson/src/dolt/go/cmd/dolt/dolt.go:604 +0x2410
main.main()
	/Users/aaronson/src/dolt/go/cmd/dolt/dolt.go:238 +0x1c

Similarly, the results from the following point to some state in the cloned database being wrong:

mkdir droptest
cd droptest
dolt init
dolt remote add pushed 'file://../pushed'
dolt push pushed main:main
dolt sql-server &
sleep 1
dolt sql -q 'call dolt_clone("file://../pushed", "cloned"); drop database cloned;'
sleep 1
dolt sql -q 'use cloned; drop database cloned;'
sleep 1
kill %1

The first query does returns

error on line 1 for query  drop database cloned: Error 1105 (HY000): database not found: cloned

The second query recovers a panic in *DoltDatabaseProvider.Close()

And then the sql-server itself panics on shutdown, same as the dolt sql invocation.

[reltuk]

Tracked this down to a divergence in create database behavior inside DatabaseProvider for a new database:

https://github.com/dolthub/dolt/blob/main/go/libraries/doltcore/sqle/database_provider.go#L662

vs. a cloned database:

https://github.com/dolthub/dolt/blob/main/go/libraries/doltcore/sqle/database_provider.go#L540

When we drop the database, we end up closing it and then returning an error. Then further attempts to drop the database panic with the invariant violation. I'll have a PR out today.