[magnusp]

Summary

LibsqlDatabaseMetaData.resolveDatabaseProductVersion() ran connection.createStatement().executeQuery(...) in a try-with-resources that wrapped only the result set. The statement stayed open after every uncached version lookup. The statement and its result set now open in one try-with-resources, so both close, the result set first.

The new leak-count case counts statements created through the test connection. The second case pins the cache, so a future uncached second lookup shows up as a second statement.

Contract basis. Hrana 3 is the source of truth for transport, values, and metadata, java.sql is the source of truth for the JDBC surface, and xerial/sqlite-jdbc is a behavioral reference only. This change is protocol-neutral. The product version still comes from select sqlite_version() through execute, and JDBC owns statement cleanup.

Red and green

Red at base 8754013 with only the new tests applied. The leak-count case fails for the intended reason. The cache case passes at base, because caching already exists; it is a guard, not a red case.

[ERROR] Tests run: 25, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.115 s <<< FAILURE! -- in com.github.magnusp.libsql.jdbc.LibsqlDatabaseMetaDataTest
[ERROR]   LibsqlDatabaseMetaDataTest.getDatabaseProductVersionClosesItsStatement:51 [the product-version lookup must close its statement]
[INFO] BUILD FAILURE

Green at head 0b33b7a.

[INFO] Tests run: 25, Failures: 0, Errors: 0, Skipped: 0 -- in com.github.magnusp.libsql.jdbc.LibsqlDatabaseMetaDataTest
[INFO] BUILD SUCCESS

Cache observation

getDatabaseProductVersion() twice through one metadata instance creates one statement. The first call opens, reads, and closes it. The second call reads cachedDatabaseProductVersion and opens nothing. getDatabaseProductVersionOpensOneStatementAcrossTwoCalls asserts the count stays at one.

Verification

Base 8754013c90b0299f7e87147702663eaa9646c12, head 0b33b7a93b292a9159bba1086a9078a34be80633.

Lane	Command	Result
1. Regression	./mvnw -pl libsql-jdbc test -Dtest=LibsqlDatabaseMetaDataTest at base and head	Base 1 failure for the intended reason, head 25 pass
2. Cached-version cases	./mvnw -pl libsql-jdbc test -Dtest='LibsqlDatabaseMetaDataTest#getDatabaseProductVersion*'	2 pass
3. Metadata cache cases	./mvnw -pl libsql-jdbc test -Dtest=LibsqlDatabaseMetaDataTest	25 pass
4. Module suite	./mvnw -pl libsql-jdbc test	223 pass, BUILD SUCCESS
5. Conformance	./mvnw -pl libsql-conformance -am verify	115 pass, 1 skipped, BUILD SUCCESS, no new divergence
6. xerial control	./mvnw -pl libsql-conformance -am -Pxerial-control verify	100 pass, 1 skipped, BUILD SUCCESS, no differences to record
7. Format	./mvnw spotless:check	BUILD SUCCESS, no violations
8. Reactor	./mvnw test	223 pass, BUILD SUCCESS
9. Vendored leak test	./mvnw -pl libsql-conformance -am verify -Dit.test=MetadataLeakTest	1 pass
10. Package	./mvnw -pl libsql-jdbc -am package -DskipTests	BUILD SUCCESS
Perf	./mvnw -pl libsql-jdbc test three times per side, interleaved	Base median 2211 ms, head median 2247 ms, +1.6 percent, within the 10 percent rule

Divergences and scope

No protocol divergence. The protocol has no statement lifecycle field, so JDBC defines it.

Caching semantics are unchanged. Issue #112 owns the failed-lookup cache and the closed-connection behavior. This PR changes statement ownership only.

Files

libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlDatabaseMetaData.java, libsql-jdbc/src/test/java/com/github/magnusp/libsql/jdbc/LibsqlDatabaseMetaDataTest.java.

Fixes #92