(ITS#7756) LMDB assertion failed in mdb_page_search_root

[xramtsov@gmail.com]

Full_Name: Evgeny Khramtsov
Version: LMDB 0.9.10
OS: Debian Linux 3.10-3-amd64 SMP
URL: http://kuku.jabber.ru/~xram/lmdb_bug.tar.gz
Submission from: (NULL) (198.211.126.52)


The way to reproduce the crash:
1) Write lots of key/vals such as "0", "1", "2", ..., "5000000" (all are "", but
this is irrelevant).
2) Delete them in the same order.
3) Get: mdb.c:4682: mdb_page_search_root: Assertion `(((mp)->mp_pb.pb.pb_lower -
((unsigned) __builtin_offsetof (MDB_page, mp_ptrs))) >> 1) > 1' failed.

On the url there is an example program reproducing the bug.
Unpack the tarball:
$ tar -xzf lmdb_bug.tar.gz
$ cd lmdb_bug
$ make
$ ./bug /path/to/some/non_existent/dir