ITS#7589 Fix delete(uneven-sized MDB_DUPFIXED data).

Do not give uneven sizes to the sub-page and the node it lives in.

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 92db028513653850cf4838f139d92483e863e8ec..5a1c1fd8df89a8c97ccd3d1a6d2644d237d655d8 100644 (file)
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -6497,21 +6497,19 @@ mdb_node_shrink(MDB_page *mp, indx_t indx)
        MDB_node *node;
        MDB_page *sp, *xp;
        char *base;
-       int osize, nsize;
-       int delta;
+       int nsize, delta;
        indx_t           i, numkeys, ptr;
 
        node = NODEPTR(mp, indx);
        sp = (MDB_page *)NODEDATA(node);
-       osize = NODEDSZ(node);
-
-       delta = sp->mp_upper - sp->mp_lower;
-       SETDSZ(node, osize - delta);
+       delta = SIZELEFT(sp);
        xp = (MDB_page *)((char *)sp + delta);
 
        /* shift subpage upward */
        if (IS_LEAF2(sp)) {
                nsize = NUMKEYS(sp) * sp->mp_pad;
+               if (nsize & 1)
+                       return;         /* do not make the node uneven-sized */
                memmove(METADATA(xp), METADATA(sp), nsize);
        } else {
                int i;
@@ -6525,6 +6523,9 @@ mdb_node_shrink(MDB_page *mp, indx_t indx)
        xp->mp_pad = sp->mp_pad;
        COPY_PGNO(xp->mp_pgno, mp->mp_pgno);
 
+       nsize = NODEDSZ(node) - delta;
+       SETDSZ(node, nsize);
+
        /* shift lower nodes upward */
        ptr = mp->mp_ptrs[indx];
        numkeys = NUMKEYS(mp);