[SV 45838] When invoking w32 programs, don't use free'd memory.

* w32/subproc/sub_proc.c (process_begin): Freeing argv[0] makes
the other argv[i] pointers invalid, so need to allocate a new
array and copy argv[i] for i != 0 first, replacing argv[0] with
the batch file name, before we can free argv[0].
1 file changed