(ITS#7126) MDB_cursor.mc_top is used uninitialized

[h.b.furuseth@usit.uio.no]

Full_Name: Hallvard B Furuseth
Version: HEAD
OS: Linux x86_64
URL: 
Submission from: (NULL) (129.240.203.186)
Submitted by: hallvard


test027-emptydn uses MDB_cursor.mc_top uninitialized.

To force a crash, initialize it to 0xdead in mdb_cursor_init()
or mdb_cursor_open().  Crash at line 4669: mdb_xcursor_init1():
    mx->mx_db.md_pad = mc->mc_pg[mc->mc_top]->mp_pad;
where mc_top is still 0xdead.

Does not happen in 2.4.28.