run MALLOC_PERTURB_=134 update-desktop-database, and it segfaults.

Program received signal SIGSEGV, Segmentation fault.
0x0000003c3b98df36 in opendir () from /lib64/libc.so.6
(gdb) bt
#0  0x0000003c3b98df36 in opendir () from /lib64/libc.so.6
#1  0x0000003a09a184d9 in g_dir_open () from /usr/lib64/libglib-2.0.so.0
#2  0x00000000004024df in process_desktop_files (
    desktop_dir=0x7979797979797979 <Address 0x7979797979797979 out of bounds>,
    prefix=0x406730 "", error=0x7fffffdfb6f0) at update-desktop-database.c:238
#3  0x0000000000402b0d in main (argc=1, argv=Variable "argv" is not available.
) at update-desktop-database.c:419
#4  0x0000003c3b91cde4 in __libc_start_main () from /lib64/libc.so.6
#5  0x0000000000402429 in _start ()
#6  0x00007fffffdfb808 in ?? ()
#7  0x0000000000000000 in ?? ()