ITS#7485 data sizes limited to 32 bits

That's all we have space for in a node record.

libraries/liblmdb/mdb.c

@@ -344,9 +344,9 @@ static txnid_t mdb_debug_start;
 
 	/**	@brief The maximum size of a key in the database.
 	 *
-	 *	While data items have essentially unbounded size, we require that
+	 *	We require that keys all fit onto a regular page. This limit
-	 *	keys all fit onto a regular page. This limit could be raised a bit
+	 *	could be raised a bit further if needed; to something just
-	 *	further if needed; to something just under #MDB_PAGESIZE / #MDB_MINKEYS.
+	 *	under #MDB_PAGESIZE / #MDB_MINKEYS.
 	 *
 	 *	Note that data items in an #MDB_DUPSORT database are actually keys
 	 *	of a subDB, so they're also limited to this size.
@@ -355,6 +355,12 @@ static txnid_t mdb_debug_start;
 #define MDB_MAXKEYSIZE	 511
 #endif
 
+	/**	@brief The maximum size of a data item.
+	 *
+	 *	We only store a 32 bit value for node sizes.
+	 */
+#define MAXDATASIZE	0xffffffffUL
+
 #if MDB_DEBUG
 	/**	A key buffer.
 	 *	@ingroup debug
@@ -4812,6 +4818,11 @@ mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
 	if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT) && data->mv_size > MDB_MAXKEYSIZE)
 		return EINVAL;
 
+#if SIZE_MAX > MAXDATASIZE
+	if (data->mv_size > MAXDATASIZE)
+		return EINVAL;
+#endif
+
 	DPRINTF("==> put db %u key [%s], size %zu, data size %zu",
 		mc->mc_dbi, DKEY(key), key ? key->mv_size:0, data->mv_size);