diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 0ca8ffd..69da48f 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -262,6 +262,7 @@ typedef struct MDB_node {
 	unsigned int	mn_ksize:12;			/* key size */
 #define F_BIGDATA	 0x01			/* data put on overflow page */
 #define F_SUBDATA	 0x02			/* data is a sub-database */
+#define F_DUPDATA	 0x04			/* data has duplicates */
 	char		mn_data[1];
 } MDB_node;
 
@@ -1763,7 +1764,7 @@ mdb_get(MDB_txn *txn, MDB_dbi dbi,
 	leaf = mdb_search_node(txn, dbi, mpp.mp_page, key, &exact, NULL);
 	if (leaf && exact) {
 		/* Return first duplicate data item */
-		if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
 			MDB_xcursor mx;
 
 			mdb_xcursor_init0(txn, dbi, &mx);
@@ -1854,17 +1855,18 @@ mdb_cursor_next(MDB_cursor *cursor, MDB_val *key, MDB_val *data, MDB_cursor_op o
 
 	assert(cursor->mc_initialized);
 
+	top = CURSOR_TOP(cursor);
+	mp = top->mp_page;
+
 	if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
-		if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
+		leaf = NODEPTR(mp, top->mp_ki);
+		if ((op == MDB_NEXT || op == MDB_NEXT_DUP) && F_ISSET(leaf->mn_flags, F_DUPDATA)) {
 			rc = mdb_cursor_next(&cursor->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
 			if (op != MDB_NEXT || rc == MDB_SUCCESS)
 				return rc;
 		}
 	}
 
-	top = CURSOR_TOP(cursor);
-	mp = top->mp_page;
-
 	DPRINTF("cursor_next: top page is %lu in cursor %p", mp->mp_pgno, (void *) cursor);
 
 	if (top->mp_ki + 1 >= NUMKEYS(mp)) {
@@ -1885,12 +1887,14 @@ mdb_cursor_next(MDB_cursor *cursor, MDB_val *key, MDB_val *data, MDB_cursor_op o
 	assert(IS_LEAF(mp));
 	leaf = NODEPTR(mp, top->mp_ki);
 
+	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+		mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, leaf);
+	}
 	if (data) {
 		if ((rc = mdb_read_data(cursor->mc_txn, leaf, data) != MDB_SUCCESS))
 			return rc;
 
-		if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
-			mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, leaf);
+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
 			rc = mdb_cursor_first(&cursor->mc_xcursor->mx_cursor, data, NULL);
 			if (rc != MDB_SUCCESS)
 				return rc;
@@ -1910,17 +1914,18 @@ mdb_cursor_prev(MDB_cursor *cursor, MDB_val *key, MDB_val *data, MDB_cursor_op o
 
 	assert(cursor->mc_initialized);
 
+	top = CURSOR_TOP(cursor);
+	mp = top->mp_page;
+
 	if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
-		if (op == MDB_PREV || op == MDB_PREV_DUP) {
+		leaf = NODEPTR(mp, top->mp_ki);
+		if ((op == MDB_PREV || op == MDB_PREV_DUP) && F_ISSET(leaf->mn_flags, F_DUPDATA)) {
 			rc = mdb_cursor_prev(&cursor->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
 			if (op != MDB_PREV || rc == MDB_SUCCESS)
 				return rc;
 		}
 	}
 
-	top = CURSOR_TOP(cursor);
-	mp = top->mp_page;
-
 	DPRINTF("cursor_prev: top page is %lu in cursor %p", mp->mp_pgno, (void *) cursor);
 
 	if (top->mp_ki == 0)  {
@@ -1943,12 +1948,14 @@ mdb_cursor_prev(MDB_cursor *cursor, MDB_val *key, MDB_val *data, MDB_cursor_op o
 	assert(IS_LEAF(mp));
 	leaf = NODEPTR(mp, top->mp_ki);
 
+	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+		mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, leaf);
+	}
 	if (data) {
 		if ((rc = mdb_read_data(cursor->mc_txn, leaf, data) != MDB_SUCCESS))
 			return rc;
 
-		if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
-			mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, leaf);
+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
 			rc = mdb_cursor_last(&cursor->mc_xcursor->mx_cursor, data, NULL);
 			if (rc != MDB_SUCCESS)
 				return rc;
@@ -1999,13 +2006,11 @@ mdb_cursor_set(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
 	cursor->mc_initialized = 1;
 	cursor->mc_eof = 0;
 
+	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+		mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, leaf);
+	}
 	if (data) {
-		MDB_val d2;
-		if ((rc = mdb_read_data(cursor->mc_txn, leaf, &d2)) != MDB_SUCCESS)
-			return rc;
-
-		if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
-			mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, leaf);
+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
 			if (op == MDB_SET || op == MDB_SET_RANGE) {
 				rc = mdb_cursor_first(&cursor->mc_xcursor->mx_cursor, data, NULL);
 			} else {
@@ -2023,9 +2028,9 @@ mdb_cursor_set(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
 					return rc;
 			}
 		} else {
-			*data = d2;
+			if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
+				return rc;
 		}
-
 	}
 
 	rc = mdb_set_key(leaf, key);
@@ -2057,14 +2062,14 @@ mdb_cursor_first(MDB_cursor *cursor, MDB_val *key, MDB_val *data)
 	cursor->mc_eof = 0;
 
 	if (data) {
-		if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
-			return rc;
-
-		if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
 			mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, leaf);
 			rc = mdb_cursor_first(&cursor->mc_xcursor->mx_cursor, data, NULL);
 			if (rc)
 				return rc;
+		} else {
+			if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
+				return rc;
 		}
 	}
 	return mdb_set_key(leaf, key);
@@ -2097,14 +2102,14 @@ mdb_cursor_last(MDB_cursor *cursor, MDB_val *key, MDB_val *data)
 	top->mp_ki = NUMKEYS(top->mp_page) - 1;
 
 	if (data) {
-		if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
-			return rc;
-
-		if (cursor->mc_txn->mt_dbs[cursor->mc_dbi].md_flags & MDB_DUPSORT) {
+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
 			mdb_xcursor_init1(cursor->mc_txn, cursor->mc_dbi, cursor->mc_xcursor, leaf);
 			rc = mdb_cursor_last(&cursor->mc_xcursor->mx_cursor, data, NULL);
 			if (rc)
 				return rc;
+		} else {
+			if ((rc = mdb_read_data(cursor->mc_txn, leaf, data)) != MDB_SUCCESS)
+				return rc;
 		}
 	}
 
@@ -2451,16 +2456,25 @@ mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
 int
 mdb_cursor_count(MDB_cursor *mc, unsigned long *countp)
 {
+	MDB_ppage	*top;
+	MDB_node	*leaf;
+
 	if (mc == NULL || countp == NULL)
 		return EINVAL;
 
 	if (!(mc->mc_txn->mt_dbs[mc->mc_dbi].md_flags & MDB_DUPSORT))
 		return EINVAL;
 
-	if (!mc->mc_xcursor->mx_cursor.mc_initialized)
-		return EINVAL;
+	top = CURSOR_TOP(mc);
+	leaf = NODEPTR(top->mp_page, top->mp_ki);
+	if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+		*countp = 1;
+	} else {
+		if (!mc->mc_xcursor->mx_cursor.mc_initialized)
+			return EINVAL;
 
-	*countp = mc->mc_xcursor->mx_txn.mt_dbs[mc->mc_xcursor->mx_cursor.mc_dbi].md_entries;
+		*countp = mc->mc_xcursor->mx_txn.mt_dbs[mc->mc_xcursor->mx_cursor.mc_dbi].md_entries;
+	}
 	return MDB_SUCCESS;
 }
 
@@ -2805,7 +2819,7 @@ mdb_del(MDB_txn *txn, MDB_dbi dbi,
 		return MDB_NOTFOUND;
 	}
 
-	if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
+	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
 		MDB_xcursor mx;
 		MDB_pageparent mp2;
 
@@ -3027,26 +3041,46 @@ mdb_put0(MDB_txn *txn, MDB_dbi dbi,
 	unsigned int	 ki;
 	MDB_node	*leaf;
 	MDB_pageparent	mpp;
-	MDB_val	xdata, *rdata;
+	MDB_val	xdata, *rdata, dkey;
 	MDB_db dummy;
+	char dbuf[PAGESIZE];
+	int do_sub = 0;
 
 	DPRINTF("==> put key %.*s, size %zu, data size %zu",
 		(int)key->mv_size, (char *)key->mv_data, key->mv_size, data->mv_size);
 
+	dkey.mv_size = 0;
 	mpp.mp_parent = NULL;
 	mpp.mp_pi = 0;
 	rc = mdb_search_page(txn, dbi, key, NULL, 1, &mpp);
 	if (rc == MDB_SUCCESS) {
 		leaf = mdb_search_node(txn, dbi, mpp.mp_page, key, &exact, &ki);
 		if (leaf && exact) {
-			if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
-				goto put_sub;
-			}
 			if (flags == MDB_NOOVERWRITE) {
 				DPRINTF("duplicate key %.*s",
 				    (int)key->mv_size, (char *)key->mv_data);
 				return MDB_KEYEXIST;
 			}
+			if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
+				/* Was a single item before, must convert now */
+				if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+					dkey.mv_size = NODEDSZ(leaf);
+					memcpy(dbuf, NODEDATA(leaf), dkey.mv_size);
+					memset(&dummy, 0, sizeof(dummy));
+					dummy.md_root = P_INVALID;
+					if (dkey.mv_size == sizeof(MDB_db)) {
+						memcpy(NODEDATA(leaf), &dummy, sizeof(dummy));
+						goto put_sub;
+					}
+					mdb_del_node(mpp.mp_page, ki);
+					do_sub = 1;
+					rdata = &xdata;
+					xdata.mv_size = sizeof(MDB_db);
+					xdata.mv_data = &dummy;
+					goto new_sub;
+				}
+				goto put_sub;
+			}
 			/* same size, just replace it */
 			if (NODEDSZ(leaf) == data->mv_size) {
 				memcpy(NODEDATA(leaf), data->mv_data, data->mv_size);
@@ -3078,20 +3112,9 @@ mdb_put0(MDB_txn *txn, MDB_dbi dbi,
 	DPRINTF("there are %u keys, should insert new key at index %i",
 		NUMKEYS(mpp.mp_page), ki);
 
-	/* For sorted dups, the data item at this level is a DB record
-	 * for a child DB; the actual data elements are stored as keys
-	 * in the child DB.
-	 */
-	if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
-		rdata = &xdata;
-		xdata.mv_size = sizeof(MDB_db);
-		xdata.mv_data = &dummy;
-		memset(&dummy, 0, sizeof(dummy));
-		dummy.md_root = P_INVALID;
-	} else {
-		rdata = data;
-	}
+	rdata = data;
 
+new_sub:
 	if (SIZELEFT(mpp.mp_page) < mdb_leaf_size(txn->mt_env, key, rdata)) {
 		rc = mdb_split(txn, dbi, &mpp.mp_page, &ki, key, rdata, P_INVALID);
 	} else {
@@ -3115,7 +3138,7 @@ mdb_put0(MDB_txn *txn, MDB_dbi dbi,
 		 * size limits on dupdata. The actual data fields of the child
 		 * DB are all zero size.
 		 */
-		if (F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
+		if (do_sub) {
 			MDB_xcursor mx;
 
 			leaf = NODEPTR(mpp.mp_page, ki);
@@ -3126,6 +3149,13 @@ put_sub:
 			xdata.mv_data = "";
 			if (flags == MDB_NODUPDATA)
 				flags = MDB_NOOVERWRITE;
+			/* converted, write the original data first */
+			if (dkey.mv_size) {
+				dkey.mv_data = dbuf;
+				rc = mdb_put0(&mx.mx_txn, mx.mx_cursor.mc_dbi, &dkey, &xdata, flags);
+				if (rc) return rc;
+				leaf->mn_flags |= F_DUPDATA;
+			}
 			rc = mdb_put0(&mx.mx_txn, mx.mx_cursor.mc_dbi, data, &xdata, flags);
 			mdb_xcursor_fini(txn, dbi, &mx);
 			memcpy(NODEDATA(leaf), &mx.mx_txn.mt_dbs[mx.mx_cursor.mc_dbi],