* gc.c (assign_heap_slot): SEGV happens cause on 64-bit platform

  sometime there should be `objs-=2` instead of `objs--`.
  patched by Sokolov Yura. ruby#92

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@34597 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

Author: authorNari

ChangeLog

@@ -1,3 +1,9 @@
+Tue Feb 14 18:07:20 2012  Narihiro Nakamura  <authornari@gmail.com>
+
+	* gc.c (assign_heap_slot): SEGV happens cause on 64-bit platform
+	  sometime there should be `objs-=2` instead of `objs--`.
+	  patched by Sokolov Yura. https://github.com/ruby/ruby/pull/92
+
 Tue Feb 14 16:00:30 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* io.c (io_setstrbuf): cut down the buffer if longer.

gc.c

@@ -1165,9 +1165,7 @@ assign_heap_slot(rb_objspace_t *objspace)
     p = (RVALUE*)((VALUE)p + sizeof(struct heaps_header));
     if ((VALUE)p % sizeof(RVALUE) != 0) {
        p = (RVALUE*)((VALUE)p + sizeof(RVALUE) - ((VALUE)p % sizeof(RVALUE)));
-       if ((HEAP_SIZE - HEAP_OBJ_LIMIT * sizeof(RVALUE)) < (size_t)((char*)p - (char*)membase)) {
-           objs--;
-       }
+       objs = (HEAP_SIZE - (size_t)((VALUE)p - (VALUE)membase))/sizeof(RVALUE);
     }
 
     lo = 0;