From 07dabe012b6e9cddd9fef59551bc3d6f6962bbf7 Mon Sep 17 00:00:00 2001
Subject: Backport-8057910: G1: BOT verification should not pass
 top

---
 .../src/share/vm/gc_implementation/g1/g1BlockOffsetTable.cpp   | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.cpp b/hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.cpp
index b908e8faf..b0b891d85 100644
--- a/hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.cpp
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.cpp
@@ -371,8 +371,9 @@ void G1BlockOffsetArray::alloc_block_work2(HeapWord** threshold_, size_t* index_
 }
 
 void G1BlockOffsetArray::verify() const {
+  assert(gsp()->bottom() < gsp()->top(), "Only non-empty regions should be verified.");
   size_t start_card = _array->index_for(gsp()->bottom());
-  size_t end_card = _array->index_for(gsp()->top());
+  size_t end_card = _array->index_for(gsp()->top() - 1);
 
   for (size_t current_card = start_card; current_card < end_card; current_card++) {
     u_char entry = _array->offset_array(current_card);
-- 
2.22.0