Fix order of rows during query; respect file order

When buidling the response to a select query, respect the order of rows as given by the file; before the selected rows were given in the reverted order.
Reported by @jockmckechnie on github.
Closes bug #479 .

(cherry picked from commit 54f6c22)

modules/db_text/dbt_res.c

@@ -82,6 +82,7 @@ dbt_result_p dbt_result_new(dbt_table_p _dtp, int *_lres, int _sz)
 	_dres->nrcols = _sz;
 	_dres->nrrows = 0;
 	_dres->rows = NULL;
+	_dres->last = NULL;
 
 	return _dres;
 clean:
@@ -291,10 +292,14 @@ int dbt_result_extract_fields(dbt_table_p _dtp, dbt_row_p _drp,
 		}
 	}
 
-	if(_dres->rows)
-		(_dres->rows)->prev = _rp;
-	_rp->next = _dres->rows;
-	_dres->rows = _rp;
+	_rp->next = NULL;
+	if (_dres->last) {
+		_dres->last->next = _rp;
+		_rp->prev = _dres->last;
+	} else {
+		_dres->rows = _rp;
+	}
+	_dres->last = _rp;
 	_dres->nrrows++;
 
 	return 0;

modules/db_text/dbt_res.h

@@ -42,6 +42,7 @@ typedef struct _dbt_result
 	int nrrows;
 	dbt_column_p colv;
 	dbt_row_p rows;
+	dbt_row_p last;
 } dbt_result_t, *dbt_result_p;
 
 //typedef db_res_t dbt_result_t, *dbt_result_p;