object.c: fix memory leak

* object.c (rb_obj_copy_ivar): allocate no memory for empty
  instance variables.  [ruby-core:64700] [Bug #10191]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47372 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 5 insertions, 2 deletions

diff --git a/object.c b/object.c
index b994539350..44cb842f0d 100644
--- a/object.c
+++ b/object.c
@@ -270,8 +270,11 @@ rb_obj_copy_ivar(VALUE dest, VALUE obj)
     }
     else {
 	long len = ROBJECT(obj)->as.heap.numiv;
-	VALUE *ptr = ALLOC_N(VALUE, len);
-	MEMCPY(ptr, ROBJECT(obj)->as.heap.ivptr, VALUE, len);
+	VALUE *ptr = 0;
+	if (len > 0) {
+	    ptr = ALLOC_N(VALUE, len);
+	    MEMCPY(ptr, ROBJECT(obj)->as.heap.ivptr, VALUE, len);
+	}
 	ROBJECT(dest)->as.heap.ivptr = ptr;
 	ROBJECT(dest)->as.heap.numiv = len;
 	ROBJECT(dest)->as.heap.iv_index_tbl = ROBJECT(obj)->as.heap.iv_index_tbl;