# HG changeset patch
# User ehelin
# Date 1416844932 -3600
#      Mon Nov 24 17:02:12 2014 +0100
# Node ID 16a3d9384e1e2ddfa03c5e1f1184a540ef37bcca
# Parent  3295daef265bab897d9a95279819e74196c02f33
8059066: CardTableModRefBS might commit the same page twice (01)

diff --git a/src/share/vm/memory/cardTableModRefBS.cpp b/src/share/vm/memory/cardTableModRefBS.cpp
--- a/src/share/vm/memory/cardTableModRefBS.cpp
+++ b/src/share/vm/memory/cardTableModRefBS.cpp
@@ -271,18 +271,19 @@ void CardTableModRefBS::resize_covered_r
       (HeapWord*) align_size_up((uintptr_t)new_end, _page_size);
     assert(new_end_aligned >= (HeapWord*) new_end,
            "align up, but less");
     // Check the other regions (excludes "ind") to ensure that
     // the new_end_aligned does not intrude onto the committed
     // space of another region.
     int ri = 0;
     for (ri = ind + 1; ri < _cur_covered_regions; ri++) {
-      if (new_end_aligned > _committed[ri].start() &&
-          new_end_aligned <= _committed[ri].end()) {
+      if (new_end_aligned > _committed[ri].start()) {
+        assert(new_end_aligned <= _committed[ri].end(),
+               "An earlier committed region can't cover a later committed region");
         // Any region containing the new end
         // should start at or beyond the region found (ind)
         // for the new end (committed regions are not expected to
         // be proper subsets of other committed regions).
         assert(_committed[ri].start() >= _committed[ind].start(),
                "New end of committed region is inconsistent");
         new_end_aligned = _committed[ri].start();
         // new_end_aligned can be equal to the start of its