MDEV-15914: Remove trx_undo_t::empty

Use the value trx_undo_t::top_undo_no == IB_ID_MAX for indicating
that an undo log is empty.

1 files changed, 10 insertions, 9 deletions

diff --git a/storage/innobase/trx/trx0roll.cc b/storage/innobase/trx/trx0roll.cc
index 4e17586ee41..0200c7dded2 100644
--- a/storage/innobase/trx/trx0roll.cc
+++ b/storage/innobase/trx/trx0roll.cc
@@ -946,8 +946,8 @@ trx_roll_pop_top_rec(
 		true, mtr);
 
 	if (prev_rec == NULL) {
-
-		undo->empty = TRUE;
+		undo->top_undo_no = IB_ID_MAX;
+		ut_ad(undo->empty());
 	} else {
 		page_t*	prev_rec_page = page_align(prev_rec);
 
@@ -959,6 +959,7 @@ trx_roll_pop_top_rec(
 		undo->top_page_no = page_get_page_no(prev_rec_page);
 		undo->top_offset  = prev_rec - prev_rec_page;
 		undo->top_undo_no = trx_undo_rec_get_undo_no(prev_rec);
+		ut_ad(!undo->empty());
 	}
 
 	return(undo_page + offset);
@@ -985,19 +986,19 @@ trx_roll_pop_top_rec_of_trx(trx_t* trx, roll_ptr_t* roll_ptr, mem_heap_t* heap)
 	trx_undo_t*	temp	= trx->rsegs.m_noredo.undo;
 	const undo_no_t	limit	= trx->roll_limit;
 
-	ut_ad(!insert || !update || insert->empty || update->empty
+	ut_ad(!insert || !update || insert->empty() || update->empty()
 	      || insert->top_undo_no != update->top_undo_no);
-	ut_ad(!insert || !temp || insert->empty || temp->empty
+	ut_ad(!insert || !temp || insert->empty() || temp->empty()
 	      || insert->top_undo_no != temp->top_undo_no);
-	ut_ad(!update || !temp || update->empty || temp->empty
+	ut_ad(!update || !temp || update->empty() || temp->empty()
 	      || update->top_undo_no != temp->top_undo_no);
 
 	if (UNIV_LIKELY_NULL(insert)
-	    && !insert->empty && limit <= insert->top_undo_no) {
+	    && !insert->empty() && limit <= insert->top_undo_no) {
 		undo = insert;
 	}
 
-	if (update && !update->empty && update->top_undo_no >= limit) {
+	if (update && !update->empty() && update->top_undo_no >= limit) {
 		if (!undo) {
 			undo = update;
 		} else if (undo->top_undo_no < update->top_undo_no) {
@@ -1005,7 +1006,7 @@ trx_roll_pop_top_rec_of_trx(trx_t* trx, roll_ptr_t* roll_ptr, mem_heap_t* heap)
 		}
 	}
 
-	if (temp && !temp->empty && temp->top_undo_no >= limit) {
+	if (temp && !temp->empty() && temp->top_undo_no >= limit) {
 		if (!undo) {
 			undo = temp;
 		} else if (undo->top_undo_no < temp->top_undo_no) {
@@ -1024,7 +1025,7 @@ trx_roll_pop_top_rec_of_trx(trx_t* trx, roll_ptr_t* roll_ptr, mem_heap_t* heap)
 		return(NULL);
 	}
 
-	ut_ad(!undo->empty);
+	ut_ad(!undo->empty());
 	ut_ad(limit <= undo->top_undo_no);
 
 	*roll_ptr = trx_undo_build_roll_ptr(