diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 5309b2f..71b025f 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -936,7 +936,7 @@ struct MDB_txn {
  *	@{
  */
 #define MDB_TXN_RDONLY		0x01		/**< read-only transaction */
-#define MDB_TXN_ERROR		0x02		/**< an error has occurred */
+#define MDB_TXN_ERROR		0x02		/**< txn is unusable after an error */
 #define MDB_TXN_DIRTY		0x04		/**< must write, even if dirty list is empty */
 #define MDB_TXN_SPILLS		0x08		/**< txn or a parent has spilled pages */
 /** @} */
@@ -1397,6 +1397,7 @@ static void mdb_audit(MDB_txn *txn)
 	mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
 	while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
 		freecount += *(MDB_ID *)data.mv_data;
+	mdb_tassert(txn, rc == MDB_NOTFOUND);
 
 	count = 0;
 	for (i = 0; i<txn->mt_numdbs; i++) {
@@ -1410,8 +1411,8 @@ static void mdb_audit(MDB_txn *txn)
 			txn->mt_dbs[i].md_leaf_pages +
 			txn->mt_dbs[i].md_overflow_pages;
 		if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
-			mdb_page_search(&mc, NULL, MDB_PS_FIRST);
-			do {
+			rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST);
+			for (; rc == MDB_SUCCESS; rc = mdb_cursor_sibling(&mc, 1)) {
 				unsigned j;
 				MDB_page *mp;
 				mp = mc.mc_pg[mc.mc_top];
@@ -1425,7 +1426,7 @@ static void mdb_audit(MDB_txn *txn)
 					}
 				}
 			}
-			while (mdb_cursor_sibling(&mc, 1) == 0);
+			mdb_tassert(txn, rc == MDB_NOTFOUND);
 		}
 	}
 	if (freecount + count + 2 /* metapages */ != txn->mt_next_pgno) {
@@ -6228,8 +6229,10 @@ put_sub:
 			/* converted, write the original data first */
 			if (dkey.mv_size) {
 				rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
-				if (rc)
-					return rc;
+				if (rc) {
+					mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
+					return rc == MDB_KEYEXIST ? MDB_CORRUPTED : rc;
+				}
 				{
 					/* Adjust other cursors pointing to mp */
 					MDB_cursor *m2;
@@ -6316,6 +6319,8 @@ mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
 				mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
 			}
 			rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);
+			if (rc)
+				return rc;
 			/* If sub-DB still has entries, we're done */
 			if (mc->mc_xcursor->mx_db.md_entries) {
 				if (leaf->mn_flags & F_SUBDATA) {
@@ -6346,10 +6351,9 @@ mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
 		if (leaf->mn_flags & F_SUBDATA) {
 			/* add all the child DB's pages to the free list */
 			rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
-			if (rc == MDB_SUCCESS) {
-				mc->mc_db->md_entries -=
-					mc->mc_xcursor->mx_db.md_entries;
-			}
+			if (rc)
+				goto fail;
+			mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries;
 		}
 	}
 
@@ -6361,11 +6365,15 @@ mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
 		memcpy(&pg, NODEDATA(leaf), sizeof(pg));
 		if ((rc = mdb_page_get(mc->mc_txn, pg, &omp, NULL)) ||
 			(rc = mdb_ovpage_free(mc, omp)))
-			return rc;
+			goto fail;
 	}
 
 del_key:
 	return mdb_cursor_del0(mc);
+
+fail:
+	mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
+	return rc;
 }
 
 /** Allocate and initialize new pages for a database.
@@ -7027,7 +7035,9 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 			unsigned int snum = csrc->mc_snum;
 			MDB_node *s2;
 			/* must find the lowest key below src */
-			mdb_page_search_lowest(csrc);
+			rc = mdb_page_search_lowest(csrc);
+			if (rc)
+				return rc;
 			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
 				key.mv_size = csrc->mc_db->md_pad;
 				key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
@@ -7050,7 +7060,9 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 		MDB_node *s2;
 		MDB_val bkey;
 		/* must find the lowest key below dst */
-		mdb_page_search_lowest(cdst);
+		rc = mdb_page_search_lowest(cdst);
+		if (rc)
+			return rc;
 		if (IS_LEAF2(cdst->mc_pg[cdst->mc_top])) {
 			bkey.mv_size = cdst->mc_db->md_pad;
 			bkey.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, bkey.mv_size);
@@ -7212,7 +7224,9 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
 				unsigned int snum = csrc->mc_snum;
 				MDB_node *s2;
 				/* must find the lowest key below src */
-				mdb_page_search_lowest(csrc);
+				rc = mdb_page_search_lowest(csrc);
+				if (rc)
+					return rc;
 				if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
 					key.mv_size = csrc->mc_db->md_pad;
 					key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
@@ -7486,9 +7500,8 @@ mdb_cursor_del0(MDB_cursor *mc)
 	mdb_node_del(mc, mc->mc_db->md_pad);
 	mc->mc_db->md_entries--;
 	rc = mdb_rebalance(mc);
-	if (rc != MDB_SUCCESS)
-		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
-	else {
+
+	if (rc == MDB_SUCCESS) {
 		MDB_cursor *m2, *m3;
 		MDB_dbi dbi = mc->mc_dbi;
 
@@ -7496,11 +7509,14 @@ mdb_cursor_del0(MDB_cursor *mc)
 		nkeys = NUMKEYS(mp);
 
 		/* if mc points past last node in page, find next sibling */
-		if (mc->mc_ki[mc->mc_top] >= nkeys)
-			mdb_cursor_sibling(mc, 1);
+		if (mc->mc_ki[mc->mc_top] >= nkeys) {
+			rc = mdb_cursor_sibling(mc, 1);
+			if (rc == MDB_NOTFOUND)
+				rc = MDB_SUCCESS;
+		}
 
 		/* Adjust other cursors pointing to mp */
-		for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
+		for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) {
 			m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
 			if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
 				continue;
@@ -7512,13 +7528,18 @@ mdb_cursor_del0(MDB_cursor *mc)
 					if (m3->mc_ki[mc->mc_top] > ki)
 						m3->mc_ki[mc->mc_top]--;
 				}
-				if (m3->mc_ki[mc->mc_top] >= nkeys)
-					mdb_cursor_sibling(m3, 1);
+				if (m3->mc_ki[mc->mc_top] >= nkeys) {
+					rc = mdb_cursor_sibling(m3, 1);
+					if (rc == MDB_NOTFOUND)
+						rc = MDB_SUCCESS;
+				}
 			}
 		}
 		mc->mc_flags |= C_DEL;
 	}
 
+	if (rc)
+		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
 	return rc;
 }
 
@@ -7626,7 +7647,7 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 
 	if (mc->mc_snum < 2) {
 		if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
-			return rc;
+			goto done;
 		/* shift current top to make room for new parent */
 		mc->mc_pg[1] = mc->mc_pg[0];
 		mc->mc_ki[1] = mc->mc_ki[0];
@@ -7644,7 +7665,7 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 			mc->mc_ki[0] = mc->mc_ki[1];
 			mc->mc_db->md_root = mp->mp_pgno;
 			mc->mc_db->md_depth--;
-			return rc;
+			goto done;
 		}
 		mc->mc_snum = 2;
 		mc->mc_top = 1;
@@ -7673,7 +7694,6 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 			int x;
 			unsigned int lsize, rsize, ksize;
 			/* Move half of the keys to the right sibling */
-			copy = NULL;
 			x = mc->mc_ki[mc->mc_top] - split_indx;
 			ksize = mc->mc_db->md_pad;
 			split = LEAF2KEY(mp, split_indx, ksize);
@@ -7720,8 +7740,10 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 
 			/* grab a page to hold a temporary copy */
 			copy = mdb_page_malloc(mc->mc_txn, 1);
-			if (copy == NULL)
-				return ENOMEM;
+			if (copy == NULL) {
+				rc = ENOMEM;
+				goto done;
+			}
 			copy->mp_pgno  = mp->mp_pgno;
 			copy->mp_flags = mp->mp_flags;
 			copy->mp_lower = PAGEHDRSZ;
@@ -7801,6 +7823,8 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 		mn.mc_top--;
 		did_split = 1;
 		rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0);
+		if (rc)
+			goto done;
 
 		/* root split? */
 		if (mn.mc_snum == mc->mc_snum) {
@@ -7837,14 +7861,14 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 	}
 	mc->mc_flags ^= C_SPLITTING;
 	if (rc != MDB_SUCCESS) {
-		return rc;
+		goto done;
 	}
 	if (nflags & MDB_APPEND) {
 		mc->mc_pg[mc->mc_top] = rp;
 		mc->mc_ki[mc->mc_top] = 0;
 		rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
 		if (rc)
-			return rc;
+			goto done;
 		for (i=0; i<mc->mc_top; i++)
 			mc->mc_ki[i] = mn.mc_ki[i];
 	} else if (!IS_LEAF2(mp)) {
@@ -7882,11 +7906,8 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 			}
 
 			rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
-			if (rc) {
-				/* return tmp page to freelist */
-				mdb_page_free(env, copy);
-				return rc;
-			}
+			if (rc)
+				goto done;
 			if (i == nkeys) {
 				i = 0;
 				j = 0;
@@ -7926,8 +7947,6 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 				}
 			}
 		}
-		/* return tmp page to freelist */
-		mdb_page_free(env, copy);
 	}
 
 	{
@@ -7978,6 +7997,12 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 		}
 	}
 	DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));
+
+done:
+	if (copy)					/* tmp page */
+		mdb_page_free(env, copy);
+	if (rc)
+		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
 	return rc;
 }
 
@@ -8317,22 +8342,22 @@ mdb_drop0(MDB_cursor *mc, int subs)
 						memcpy(&pg, NODEDATA(ni), sizeof(pg));
 						rc = mdb_page_get(txn, pg, &omp, NULL);
 						if (rc != 0)
-							return rc;
+							goto done;
 						mdb_cassert(mc, IS_OVERFLOW(omp));
 						rc = mdb_midl_append_range(&txn->mt_free_pgs,
 							pg, omp->mp_pages);
 						if (rc)
-							return rc;
+							goto done;
 					} else if (subs && (ni->mn_flags & F_SUBDATA)) {
 						mdb_xcursor_init1(mc, ni);
 						rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
 						if (rc)
-							return rc;
+							goto done;
 					}
 				}
 			} else {
 				if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)
-					return rc;
+					goto done;
 				for (i=0; i<n; i++) {
 					pgno_t pg;
 					ni = NODEPTR(mp, i);
@@ -8346,6 +8371,8 @@ mdb_drop0(MDB_cursor *mc, int subs)
 			mc->mc_ki[mc->mc_top] = i;
 			rc = mdb_cursor_sibling(mc, 1);
 			if (rc) {
+				if (rc != MDB_NOTFOUND)
+					goto done;
 				/* no more siblings, go back to beginning
 				 * of previous level.
 				 */
@@ -8359,6 +8386,9 @@ mdb_drop0(MDB_cursor *mc, int subs)
 		}
 		/* free it */
 		rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);
+done:
+		if (rc)
+			txn->mt_flags |= MDB_TXN_ERROR;
 	} else if (rc == MDB_NOTFOUND) {
 		rc = MDB_SUCCESS;
 	}
@@ -8393,6 +8423,8 @@ int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
 		if (!rc) {
 			txn->mt_dbflags[dbi] = DB_STALE;
 			mdb_dbi_close(txn->mt_env, dbi);
+		} else {
+			txn->mt_flags |= MDB_TXN_ERROR;
 		}
 	} else {
 		/* reset the DB record, mark it dirty */