branches/zip: buf_page_set_old(): Add the assertion ut_ad(bpage->in_LRU_list).

Adjust the callers where necessary:
buf_LRU_add_block_to_end_low() and buf_LRU_add_block_low().

buf/buf0lru.c

@@ -974,8 +974,6 @@ buf_LRU_add_block_to_end_low(
 
 	ut_a(buf_page_in_file(bpage));
 
-	buf_page_set_old(bpage, TRUE);
-
 	last_bpage = UT_LIST_GET_LAST(buf_pool->LRU);
 
 	if (last_bpage) {
@@ -988,6 +986,8 @@ buf_LRU_add_block_to_end_low(
 	UT_LIST_ADD_LAST(LRU, buf_pool->LRU, bpage);
 	ut_d(bpage->in_LRU_list = TRUE);
 
+	buf_page_set_old(bpage, TRUE);
+
 	if (UT_LIST_GET_LEN(buf_pool->LRU) >= BUF_LRU_OLD_MIN_LEN) {
 
 		buf_pool->LRU_old_len++;
@@ -1035,8 +1035,6 @@ buf_LRU_add_block_low(
 	ut_a(buf_page_in_file(bpage));
 	ut_ad(!bpage->in_LRU_list);
 
-	buf_page_set_old(bpage, old);
-
 	if (!old || (UT_LIST_GET_LEN(buf_pool->LRU) < BUF_LRU_OLD_MIN_LEN)) {
 
 		UT_LIST_ADD_FIRST(LRU, buf_pool->LRU, bpage);
@@ -1056,6 +1054,8 @@ buf_LRU_add_block_low(
 
 	ut_d(bpage->in_LRU_list = TRUE);
 
+	buf_page_set_old(bpage, old);
+
 	if (UT_LIST_GET_LEN(buf_pool->LRU) > BUF_LRU_OLD_MIN_LEN) {
 
 		ut_ad(buf_pool->LRU_old);

include/buf0buf.ic

@@ -444,6 +444,7 @@ buf_page_set_old(
 {
 	ut_a(buf_page_in_file(bpage));
 	ut_ad(buf_pool_mutex_own());
+	ut_ad(bpage->in_LRU_list);
 
 	bpage->old = old;
 }