Fix root split check in mdb_page_split

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 33bf5d117a672e5791f58a5d7d87ae7ba33e096b..87d5feec7cafa6fb4a7209ad2a24ef4b054ed9a9 100644 (file)
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -1074,7 +1074,7 @@ mdb_cursor_chk(MDB_cursor *mc)
        MDB_node *node;
        MDB_page *mp;
 
-       if (!mc->mc_snum) return;
+       if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return;
        for (i=0; i<mc->mc_top; i++) {
                mp = mc->mc_pg[i];
                node = NODEPTR(mp, mc->mc_ki[i]);
@@ -5765,7 +5765,7 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
        unsigned int nflags)
 {
        unsigned int flags;
-       int              rc = MDB_SUCCESS, ins_new = 0, new_root = 0, newpos = 1;
+       int              rc = MDB_SUCCESS, ins_new = 0, new_root = 0, newpos = 1, did_split = 0;
        indx_t           newindx;
        pgno_t           pgno = 0;
        unsigned int     i, j, split_indx, nkeys, pmax;
@@ -5834,6 +5834,8 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 
        nkeys = NUMKEYS(mp);
        split_indx = (nkeys + 1) / 2;
+       if (newindx < split_indx)
+               newpos = 0;
 
        if (IS_LEAF2(rp)) {
                char *split, *ins;
@@ -5953,32 +5955,30 @@ newsep:
        if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(mc->mc_txn->mt_env, &sepkey)) {
                mn.mc_snum--;
                mn.mc_top--;
+               did_split = 1;
                rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0);
 
+               /* root split? */
+               if (mn.mc_snum == mc->mc_snum) {
+                       mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top];
+                       mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top];
+                       mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop];
+                       mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop];
+                       mc->mc_snum++;
+                       mc->mc_top++;
+                       ptop++;
+               }
                /* Right page might now have changed parent.
                 * Check if left page also changed parent.
                 */
                if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
                    mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
-                       /* root split? */
-                       if (mn.mc_snum == mc->mc_snum) {
-                               mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top];
-                               mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top];
-                               mc->mc_ki[mc->mc_top] = mn.mc_ki[mc->mc_top] - 1;
-                               mc->mc_pg[mc->mc_top] = mn.mc_pg[mc->mc_top];
-                               for (i=0; i<mc->mc_top; i++) {
-                                       mc->mc_pg[i] = mn.mc_pg[i];
-                                       mc->mc_ki[i] = mn.mc_ki[i];
-                               }
-                               mc->mc_snum++;
-                               mc->mc_top++;
-                               ptop++;
-                       } else {
-                               for (i=0; i<ptop; i++)
-                                       mc->mc_ki[i] = mn.mc_ki[i];
-                               mc->mc_pg[ptop] = mn.mc_pg[ptop];
-                               mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
+                       for (i=0; i<ptop; i++) {
+                               mc->mc_pg[i] = mn.mc_pg[i];
+                               mc->mc_ki[i] = mn.mc_ki[i];
                        }
+                       mc->mc_pg[ptop] = mn.mc_pg[ptop];
+                       mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
                }
        } else {
                mn.mc_top--;
@@ -6094,6 +6094,7 @@ done:
                /* Adjust other cursors pointing to mp */
                MDB_cursor *m2, *m3;
                MDB_dbi dbi = mc->mc_dbi;
+               int fixup = NUMKEYS(mp);
 
                if (mc->mc_flags & C_SUB)
                        dbi--;
@@ -6127,14 +6128,12 @@ done:
                        if (m3->mc_pg[mc->mc_top] == mp) {
                                if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
                                        m3->mc_ki[mc->mc_top]++;
-                               if (m3->mc_ki[mc->mc_top] >= split_indx) {
+                               if (m3->mc_ki[mc->mc_top] >= fixup) {
                                        m3->mc_pg[mc->mc_top] = rp;
-                                       m3->mc_ki[mc->mc_top] -= split_indx;
-                                       if ((nflags & MDB_SPLIT_REPLACE) && !newpos)
-                                               m3->mc_ki[mc->mc_top]--;
+                                       m3->mc_ki[mc->mc_top] -= fixup;
                                        m3->mc_ki[ptop] = mn.mc_ki[ptop];
                                }
-                       } else if (m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
+                       } else if (!did_split && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
                                m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
                                m3->mc_ki[ptop]++;
                        }