Do not rollback in TxError

Fixes #2153. Not so sure if SQLite doesn't rollback in more cases, we
should definitively check this out.

tests/integration/query_processing/test_transactions.rs

@@ -0,0 +1,26 @@
+use turso_core::{LimboError, Result, StepResult, Value};
+
+use crate::common::TempDatabase;
+
+#[test]
+fn test_txn_error_doesnt_rollback_txn() -> Result<()> {
+    let tmp_db = TempDatabase::new_with_rusqlite("create table t(x);", false);
+    let conn = tmp_db.connect_limbo();
+
+    conn.execute("begin")?;
+    conn.execute("insert into t values (1)")?;
+    // should fail
+    assert!(conn
+        .execute("begin")
+        .inspect_err(|e| assert!(matches!(e, LimboError::TxError(_))))
+        .is_err());
+    conn.execute("insert into t values (1)")?;
+    conn.execute("commit")?;
+    let mut stmt = conn.query("select sum(x) from t")?.unwrap();
+    if let StepResult::Row = stmt.step()? {
+        let row = stmt.row().unwrap();
+        assert_eq!(*row.get::<&Value>(0).unwrap(), Value::Integer(2));
+    }
+
+    Ok(())
+}