Make a copy of any environment string we are going to modify when
we are cleaning up the environment before an exec, otherwise we
will seg fault if the string is read only. Fixes #270326.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12001 a5019735-40e9-0310-863c-91ae7b9d1cf9
1 file changed