Avoid error after upgrading a database

The `runUpgrade` query server command is mistakenly caching the old
dbscheme in memory after running the upgrade. The problem is in the
CLI. The workaround is to restart the query server after running an
upgrade. This is not a great solution, but considering that explicit
upgrades are now very rare. I do not think it is worth putting in
too much effort for a proper fix.

Author: aeisenberg

extensions/ql-vscode/src/upgrades.ts

@@ -194,7 +194,14 @@ export async function upgradeDatabaseExplicit(
       void qs.logger.log('Running the following database upgrade:');
 
       getUpgradeDescriptions(compileUpgradeResult.compiledUpgrades).map(s => s.description).join('\n');
-      return await runDatabaseUpgrade(qs, dbItem, compileUpgradeResult.compiledUpgrades, progress, token);
+      const result = await runDatabaseUpgrade(qs, dbItem, compileUpgradeResult.compiledUpgrades, progress, token);
+
+      // TODO Can remove the next lines when https://github.com/github/codeql-team/issues/1241 is fixed
+      // restart the query server to avoid a bug in the CLI where the upgrade is applied, but the old dbscheme
+      // is still cached in memory.
+
+      await qs.restartQueryServer(progress, token);
+      return result;
     }
     catch (e) {
       void showAndLogErrorMessage(`Database upgrade failed: ${e}`);