diff --git a/libraries/liblmdb/CHANGES b/libraries/liblmdb/CHANGES
index d69c6aec40..454e6247b5 100644
--- a/libraries/liblmdb/CHANGES
+++ b/libraries/liblmdb/CHANGES
@@ -1,11 +1,13 @@
 LMDB 0.9 Change Log
 
 LMDB 0.9.19 Release Engineering
-    Tweak Win32 error message buffer
-    Fix MDB_GET_BOTH on non-dup record (ITS#8393)
-    Optimize mdb_drop
-    Fix xcursors after mdb_cursor_del (ITS#8406)
-    Fix MDB_NEXT_DUP after mdb_cursor_del (ITS#8412)
+	Fix mdb_env_cwalk cursor init (ITS#8424)
+	Fix robust mutexes on Solaris 10/11 (ITS#8339)
+	Tweak Win32 error message buffer
+	Fix MDB_GET_BOTH on non-dup record (ITS#8393)
+	Optimize mdb_drop
+	Fix xcursors after mdb_cursor_del (ITS#8406)
+	Fix MDB_NEXT_DUP after mdb_cursor_del (ITS#8412)
 
 LMDB 0.9.18 Release (2016/02/05)
 	Fix robust mutex detection on glibc 2.10-11 (ITS#8330)
diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 0ac5abbff7..1edc282b81 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -257,7 +257,8 @@ typedef SSIZE_T	ssize_t;
 # else
 #  define MDB_USE_ROBUST	1
 /* glibc < 2.12 only provided _np API */
-#  if defined(__GLIBC__) && GLIBC_VER < 0x02000c
+#  if (defined(__GLIBC__) && GLIBC_VER < 0x02000c) || \
+	(defined(PTHREAD_MUTEX_ROBUST_NP) && !defined(PTHREAD_MUTEX_ROBUST))
 #   define PTHREAD_MUTEX_ROBUST	PTHREAD_MUTEX_ROBUST_NP
 #   define pthread_mutexattr_setrobust(attr, flag)	pthread_mutexattr_setrobust_np(attr, flag)
 #   define pthread_mutex_consistent(mutex)	pthread_mutex_consistent_np(mutex)
@@ -4620,15 +4621,25 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 #else	/* MDB_USE_POSIX_MUTEX: */
 		pthread_mutexattr_t mattr;
 
-		if ((rc = pthread_mutexattr_init(&mattr))
-			|| (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
-#ifdef MDB_ROBUST_SUPPORTED
-			|| (rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST))
-#endif
-			|| (rc = pthread_mutex_init(env->me_txns->mti_rmutex, &mattr))
-			|| (rc = pthread_mutex_init(env->me_txns->mti_wmutex, &mattr)))
+		/* Solaris needs this before initing a robust mutex.  Otherwise
+		 * it may skip the init and return EBUSY "seems someone already
+		 * inited" or EINVAL "it was inited differently".
+		 */
+		memset(env->me_txns->mti_rmutex, 0, sizeof(*env->me_txns->mti_rmutex));
+		memset(env->me_txns->mti_wmutex, 0, sizeof(*env->me_txns->mti_wmutex));
+
+		if ((rc = pthread_mutexattr_init(&mattr)))
 			goto fail;
+
+		rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
+#ifdef MDB_ROBUST_SUPPORTED
+		if (!rc) rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST);
+#endif
+		if (!rc) rc = pthread_mutex_init(env->me_txns->mti_rmutex, &mattr);
+		if (!rc) rc = pthread_mutex_init(env->me_txns->mti_wmutex, &mattr);
 		pthread_mutexattr_destroy(&mattr);
+		if (rc)
+			goto fail;
 #endif	/* _WIN32 || MDB_USE_POSIX_SEM */
 
 		env->me_txns->mti_magic = MDB_MAGIC;
@@ -6635,8 +6646,13 @@ current:
 					/* Note - this page is already counted in parent's dirty_room */
 					rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
 					mdb_cassert(mc, rc2 == 0);
+					/* Currently we make the page look as with put() in the
+					 * parent txn, in case the user peeks at MDB_RESERVEd
+					 * or unused parts. Some users treat ovpages specially.
+					 */
 					if (!(flags & MDB_RESERVE)) {
-						/* Copy end of page, adjusting alignment so
+						/* Skip the part where LMDB will put *data.
+						 * Copy end of page, adjusting alignment so
 						 * compiler may copy words instead of bytes.
 						 */
 						off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
@@ -8885,7 +8901,7 @@ mdb_env_cthr_toggle(mdb_copy *my, int st)
 static int ESECT
 mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
 {
-	MDB_cursor mc;
+	MDB_cursor mc = {0};
 	MDB_txn *txn = my->mc_txn;
 	MDB_node *ni;
 	MDB_page *mo, *mp, *leaf;
@@ -8898,7 +8914,6 @@ mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
 		return MDB_SUCCESS;
 
 	mc.mc_snum = 1;
-	mc.mc_top = 0;
 	mc.mc_txn = txn;
 
 	rc = mdb_page_get(my->mc_txn, *pg, &mc.mc_pg[0], NULL);