Fix a Massif bug:  when realloc'ing a block, any values in the part of the
block beyond the original request weren't copied.  They are now.  This is
important because a program could use malloc_usable_size to gain legitimate
access to those extra bytes.



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11956 a5019735-40e9-0310-863c-91ae7b9d1cf9
6 files changed