fix: EXPOSED-621 IllegalStateException on accessing autoincrement col…

…umn after insert using Entity (#2291)

The issue was that the `hashCode()` function was using `sequence` which invokes `autoincSeq` if `_sequence` is null, which then invokes `currentDialect`, and if this is not within a transaction, it will throw an error. This was introduced in the pull request for EXPOSED-487. The fix is to use `_sequence` instead of `sequence` when generating a hashcode.

exposed-core/src/main/kotlin/org/jetbrains/exposed/sql/ColumnType.kt

@@ -204,7 +204,7 @@ class AutoIncColumnType<T>(
         var result = delegate.hashCode()
         result = 31 * result + (_autoincSeq?.hashCode() ?: 0)
         result = 31 * result + fallbackSeqName.hashCode()
-        result = 31 * result + (sequence?.hashCode() ?: 0)
+        result = 31 * result + (_sequence?.hashCode() ?: 0)
         return result
     }
 }

exposed-tests/src/test/kotlin/org/jetbrains/exposed/sql/tests/shared/ddl/SequencesTests.kt

@@ -1,8 +1,11 @@
 package org.jetbrains.exposed.sql.tests.shared.ddl
 
+import org.jetbrains.exposed.dao.UUIDEntity
+import org.jetbrains.exposed.dao.UUIDEntityClass
 import org.jetbrains.exposed.dao.id.EntityID
 import org.jetbrains.exposed.dao.id.IdTable
 import org.jetbrains.exposed.dao.id.LongIdTable
+import org.jetbrains.exposed.dao.id.UUIDTable
 import org.jetbrains.exposed.sql.*
 import org.jetbrains.exposed.sql.tests.DatabaseTestsBase
 import org.jetbrains.exposed.sql.tests.TestDB
@@ -11,8 +14,12 @@ import org.jetbrains.exposed.sql.tests.inProperCase
 import org.jetbrains.exposed.sql.tests.shared.assertEquals
 import org.jetbrains.exposed.sql.tests.shared.assertFalse
 import org.jetbrains.exposed.sql.tests.shared.assertTrue
+import org.jetbrains.exposed.sql.transactions.transaction
 import org.jetbrains.exposed.sql.vendors.currentDialect
+import org.junit.Assume
 import org.junit.Test
+import java.util.*
+import kotlin.test.assertEquals
 import kotlin.test.assertNotNull
 import kotlin.test.assertNull
 
@@ -311,6 +318,43 @@ class SequencesTests : DatabaseTestsBase() {
         }
     }
 
+    @Test
+    fun testAutoIncrementColumnAccessWithEntity() {
+        Assume.assumeTrue(TestDB.POSTGRESQL in TestDB.enabledDialects())
+
+        TestDB.POSTGRESQL.connect()
+
+        try {
+            transaction {
+                SchemaUtils.create(TesterTable)
+            }
+
+            val testerEntity = transaction {
+                TesterEntity.new {
+                    name = "test row"
+                }
+            }
+
+            assertEquals(1, testerEntity.index)
+        } finally {
+            transaction {
+                SchemaUtils.drop(TesterTable)
+            }
+        }
+    }
+
+    object TesterTable : UUIDTable("Tester") {
+        val index = integer("index").autoIncrement()
+        val name = text("name")
+    }
+
+    class TesterEntity(id: EntityID<UUID>) : UUIDEntity(id) {
+        companion object : UUIDEntityClass<TesterEntity>(TesterTable)
+
+        var index by TesterTable.index
+        var name by TesterTable.name
+    }
+
     private object Developer : Table() {
         val id = integer("id")
         val name = varchar("name", 25)