From 4681620e66bbd0973bb441edf4910e9c8a2d9c52 Mon Sep 17 00:00:00 2001
From: Leo Yuriev <leo@yuriev.ru>
Date: Thu, 2 Feb 2017 13:15:16 +0300
Subject: [PATCH] mdbx: don't ignore `data` arg in mdb_del() for libfpta.

---
 lmdb.h | 10 +++++++++-
 mdb.c  |  2 ++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/lmdb.h b/lmdb.h
index 7463e4e8..b6a55f11 100644
--- a/lmdb.h
+++ b/lmdb.h
@@ -1,7 +1,7 @@
 /** @file lmdb.h
  *	@brief Extended Lightning memory-mapped database library
  *
- *	@mainpage	Extended Lightning Memory-Mapped Database Manager (MDBX)
+ *	@mainpage	Extended Lightning Memory-Mapped Database (MDBX)
  *
  *	@section intro_sec Introduction
  *	MDBX is a Btree-based database management library modeled loosely on the
@@ -1387,12 +1387,20 @@ int  mdb_put(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data,
 	/** @brief Delete items from a database.
 	 *
 	 * This function removes key/data pairs from the database.
+	 *
+	 * MDBX-mode:
+	 * The data parameter is NOT ignored regardless the database does
+	 * support sorted duplicate data items or not. If the data parameter
+	 * is non-NULL only the matching data item will be deleted.
+	 *
+	 * LMDB-compatible mode:
 	 * If the database does not support sorted duplicate data items
 	 * (#MDB_DUPSORT) the data parameter is ignored.
 	 * If the database supports sorted duplicates and the data parameter
 	 * is NULL, all of the duplicate data items for the key will be
 	 * deleted. Otherwise, if the data parameter is non-NULL
 	 * only the matching data item will be deleted.
+	 *
 	 * This function will return #MDB_NOTFOUND if the specified key/data
 	 * pair is not in the database.
 	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
diff --git a/mdb.c b/mdb.c
index 8b4afd00..449ba82f 100644
--- a/mdb.c
+++ b/mdb.c
@@ -8773,10 +8773,12 @@ mdb_del(MDB_txn *txn, MDB_dbi dbi,
 	if (unlikely(txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED)))
 		return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
 
+#if ! MDBX_MODE_ENABLED
 	if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
 		/* must ignore any data */
 		data = NULL;
 	}
+#endif
 
 	return mdb_del0(txn, dbi, key, data, 0);
 }