Comment ovpage code in mdb_cursor_put()

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 72294a7e519867a3539384545081d0c763f723a9..f3ca42755c381c4d1038be74d2da108d784a7798 100644 (file)
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -7468,8 +7468,13 @@ 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);