From 79844bd44687dd5ecdf8ab36144584db06939dc7 Mon Sep 17 00:00:00 2001
From: Hallvard Furuseth <hallvard@openldap.org>
Date: Thu, 13 Jun 2013 08:58:24 +0200
Subject: [PATCH] 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.
---
 libraries/liblmdb/mdb.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 2791e79..e1093f6 100644
--- 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)