BatchUpdateStatement expects set(..) calls in alphabetical order and fails when given more than 2 batches

[jon-mey]

BatchUpdateStatement produces wrong SQL when the set(..) calls are not in alphabetical order for columns:

object Test : IntIdTable() {
    val a = integer("a")
    val b = float("b")
    val c = text("c")
}

...

transaction {
    addLogger(StdOutSqlLogger)

    BatchUpdateStatement(Test).apply {
        listOf(1).forEach {
            addBatch(EntityID(it, Test))
            this[Test.c] = "3"
            this[Test.a] = 1
            this[Test.b] = 2.0f

        }
    }.execute(this)
}

This produces:
SQL: UPDATE TEST SET C=1, A=2.0, B='3' WHERE ID = 1

If the order is changed like this it works correctly:

transaction {
    addLogger(StdOutSqlLogger)

    BatchUpdateStatement(Test).apply {
        listOf(1).forEach {
            addBatch(EntityID(it, Test))
            this[Test.a] = 1
            this[Test.b] = 2.0f
            this[Test.c] = "3"
        }
    }.execute(this)
}

[jon-mey]

It also fails if you add more than 2 batches to the statement:

transaction {
    addLogger(StdOutSqlLogger)

    BatchUpdateStatement(Test).apply {
        listOf(1, 2, 3).forEach {
            addBatch(EntityID(it, Test))
            this[Test.a] = 1
            this[Test.b] = 2.0f
            this[Test.c] = "3"
        }
    }.execute(this)
}

org.jetbrains.exposed.sql.statements.BatchDataInconsistentException: Some values missing for batch update. Different columns: [Test.a, Test.b, Test.c]

Looking at the source code:

val different by lazy {  data.first().second.keys.intersect(lastBatch!!.second.keys) }

This will make 'different' contain all keys on the third iteration.