# HG changeset patch
# User ehelin
# Date 1505479633 -7200
# Node ID 4f26db3c02af7b330403fdc95369bc2d3e9140e9
# Parent  6210a27c3704a9d1d2441b3e2428ff128165b8a2
8187578: BitMap::reallocate should check if old_map is NULL
Reviewed-by: stefank, eosterlund, dholmes

diff -r 6210a27c3704 -r 4f26db3c02af src/hotspot/share/utilities/bitMap.cpp
--- a/src/hotspot/share/utilities/bitMap.cpp	Tue Oct 10 19:18:36 2017 -0700
+++ b/src/hotspot/share/utilities/bitMap.cpp	Fri Sep 15 14:47:13 2017 +0200
@@ -81,8 +81,10 @@
   if (new_size_in_words > 0) {
     map = allocator.allocate(new_size_in_words);
 
-    Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) map,
-                         MIN2(old_size_in_words, new_size_in_words));
+    if (old_map != NULL) {
+      Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) map,
+                           MIN2(old_size_in_words, new_size_in_words));
+    }
 
     if (new_size_in_words > old_size_in_words) {
       clear_range_of_words(map, old_size_in_words, new_size_in_words);