ITS#7594 Fix MDB cursor tracking with subDBs.

The tracking code should not change the current cursor.
It did when that was a C_SUB cursor, which should not be
checked against the tracked cursors but their xcursors.

However, do not bother to skip the tracking code for the
current cursor when it would not change that cursor anyway.

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 2791e798e79cc1f003f0dbb2c61005fefbc19684..e1093f6467a85755d61462e9bea883e38b67a35d 100644 (file)
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -1621,8 +1621,8 @@ finish:
                        MDB_dbi dbi = mc->mc_dbi-1;
 
                        for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
-                               if (m2 == mc) continue;
                                m3 = &m2->mc_xcursor->mx_cursor;
+                               if (m3 == mc) continue;
                                if (m3->mc_snum < mc->mc_snum) continue;
                                if (m3->mc_pg[mc->mc_top] == mc->mc_pg[mc->mc_top]) {
                                        m3->mc_pg[mc->mc_top] = mp;
@@ -6236,11 +6236,11 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
                        dbi--;
 
                for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
-                       if (m2 == csrc) continue;
                        if (csrc->mc_flags & C_SUB)
                                m3 = &m2->mc_xcursor->mx_cursor;
                        else
                                m3 = m2;
+                       if (m3 == csrc) continue;
                        if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] ==
                                csrc->mc_ki[csrc->mc_top]) {
                                m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
@@ -6496,10 +6496,10 @@ mdb_rebalance(MDB_cursor *mc)
                        mc->mc_db->md_depth = 0;
                        mc->mc_db->md_leaf_pages = 0;
                        mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
+                       /* Adjust cursors pointing to mp */
                        mc->mc_snum = 0;
                        mc->mc_top = 0;
                        {
-                               /* Adjust other cursors pointing to mp */
                                MDB_cursor *m2, *m3;
                                MDB_dbi dbi = mc->mc_dbi;
 
@@ -6507,7 +6507,6 @@ mdb_rebalance(MDB_cursor *mc)
                                        dbi--;
 
                                for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
-                                       if (m2 == mc) continue;
                                        if (mc->mc_flags & C_SUB)
                                                m3 = &m2->mc_xcursor->mx_cursor;
                                        else
@@ -6537,12 +6536,11 @@ mdb_rebalance(MDB_cursor *mc)
                                        dbi--;
 
                                for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
-                                       if (m2 == mc) continue;
                                        if (mc->mc_flags & C_SUB)
                                                m3 = &m2->mc_xcursor->mx_cursor;
                                        else
                                                m3 = m2;
-                                       if (m3->mc_snum < mc->mc_snum) continue;
+                                       if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
                                        if (m3->mc_pg[0] == mp) {
                                                m3->mc_pg[0] = mc->mc_pg[0];
                                                m3->mc_snum = 1;
@@ -7069,11 +7067,12 @@ done:
                        dbi--;
 
                for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
-                       if (m2 == mc) continue;
                        if (mc->mc_flags & C_SUB)
                                m3 = &m2->mc_xcursor->mx_cursor;
                        else
                                m3 = m2;
+                       if (m3 == mc)
+                               continue;
                        if (!(m3->mc_flags & C_INITIALIZED))
                                continue;
                        if (m3->mc_flags & C_SPLITTING)