ITS#7829 fix rebalance

Fixup cursor state after node_move/page_merge

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 4e9162f2e2eafd00cab72f87161fe4d87eea5dc1..af190c6afd361735d557c48b2dff79c6aa9bf4a4 100644 (file)
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -7323,6 +7323,7 @@ mdb_rebalance(MDB_cursor *mc)
        int rc;
        unsigned int ptop, minkeys;
        MDB_cursor      mn;
+       indx_t oldki;
 
        minkeys = 1 + (IS_BRANCH(mc->mc_pg[mc->mc_top]));
        DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",
@@ -7427,6 +7428,7 @@ mdb_rebalance(MDB_cursor *mc)
        mdb_cursor_copy(mc, &mn);
        mn.mc_xcursor = NULL;
 
+       oldki = mc->mc_ki[mc->mc_top];
        if (mc->mc_ki[ptop] == 0) {
                /* We're the leftmost leaf in our parent.
                 */
@@ -7460,17 +7462,21 @@ mdb_rebalance(MDB_cursor *mc)
         * (A branch page must never have less than 2 keys.)
         */
        minkeys = 1 + (IS_BRANCH(mn.mc_pg[mn.mc_top]));
-       if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys)
-               return mdb_node_move(&mn, mc);
-       else {
-               if (mc->mc_ki[ptop] == 0)
+       if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
+               rc = mdb_node_move(&mn, mc);
+               mc->mc_ki[mc->mc_top] = oldki;
+       } else {
+               if (mc->mc_ki[ptop] == 0) {
                        rc = mdb_page_merge(&mn, mc);
-               else {
+                       mc->mc_ki[mc->mc_top] = oldki;
+               } else {
+                       unsigned int nkeys = NUMKEYS(mn.mc_pg[mn.mc_top]);
                        mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
                        rc = mdb_page_merge(mc, &mn);
                        mdb_cursor_copy(&mn, mc);
+                       mc->mc_ki[mc->mc_top] = oldki + nkeys;
                }
-               mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
+               mc->mc_flags &= ~C_EOF;
        }
        return rc;
 }