bug report:"App crashes on invalid username input instead of throwing an error

[chainray01]

Describe the issue

When entering an invalid username, the application crashes with the following error: Fatal error: Range requires lowerBound <= upperBound.

Vapor version

2.13.5

Operating system and version

macos 13.7.6

Swift version

Swift Package Manager - Swift 5.9.0

Steps to reproduce

1.Enter an invalid username
2. run code
do { _ = try await pool.withConnection { conn in conn.simpleQuery("SELECT 1") }.get() } catch { throw error }

Outcome

App crashes
Swift/arm64e-apple-macos.swiftinterface:5830: Fatal error: Range requires lowerBound <= upperBound

Additional notes

No response

[chainray01]

@gwynne soft reminder

[fabianfett]

I just tried to repro this with this test case:

func testCrash2() async throws {
    var mlogger = Logger(label: "test")
    mlogger.logLevel = .debug
    let logger = mlogger
    let eventLoopGroup = MultiThreadedEventLoopGroup(numberOfThreads: 8)
    self.addTeardownBlock {
        try await eventLoopGroup.shutdownGracefully()
    }

    var clientConfig = PostgresClient.Configuration.makeTestConfiguration()
    clientConfig.username = "wrong"
    let client = PostgresClient(configuration: clientConfig, eventLoopGroup: eventLoopGroup, backgroundLogger: logger)
    do {
        try await withThrowingTaskGroup(of: Void.self) { taskGroup in
            taskGroup.addTask {
                await client.run()
            }

            do {
                _ = try await client.withConnection { conn in
                    conn.simpleQuery("SELECT 1") }.get()
            } catch {
                throw error
            }

            taskGroup.cancelAll()
        }
    } catch {
        XCTFail("Unexpected error: \(String(reflecting: error))")
    }
}

Sadly, no luck!

Observations:

• With a wrong username we shouldn't even enter the sasl handshake dance. The Postgres server rejects the startup message right away.

@chainray01 Which Postgres version do you use? Which PostgresNIO version do you use? What is the username and password that you use? (Please change it after disclosing it here, but I need it to repro your crash I'm afraid.)

[chainray01]

@fabianfett Postgres version 17,PostgresKit 2.13.5,username:dev_owner1

Kapture.2025-04-09.at.16.00.24.webm