From 36a86bbc6e3462a91cb67876dca128bcc87d927d Mon Sep 17 00:00:00 2001
From: Leo Yuriev <leo@yuriev.ru>
Date: Mon, 26 Mar 2018 20:16:18 +0300
Subject: [PATCH] mdbx: fix cursor tracking inside mdbx_rebalance().

---
 src/mdbx.c | 31 +++++++++++++------------------
 1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/src/mdbx.c b/src/mdbx.c
index 2c52f7c3..c414266b 100644
--- a/src/mdbx.c
+++ b/src/mdbx.c
@@ -8935,27 +8935,22 @@ static int mdbx_rebalance(MDBX_cursor *mc) {
       if (unlikely(rc))
         return rc;
       /* Adjust cursors pointing to mp */
+      const MDBX_dbi dbi = mc->mc_dbi;
+      for (MDBX_cursor *m2 = mc->mc_txn->mt_cursors[dbi]; m2;
+           m2 = m2->mc_next) {
+        MDBX_cursor *m3 =
+            (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
+        if (!(m3->mc_flags & C_INITIALIZED) || (m3->mc_snum < mc->mc_snum))
+          continue;
+        if (m3->mc_pg[0] == mp) {
+          m3->mc_snum = 0;
+          m3->mc_top = 0;
+          m3->mc_flags &= ~C_INITIALIZED;
+        }
+      }
       mc->mc_snum = 0;
       mc->mc_top = 0;
       mc->mc_flags &= ~C_INITIALIZED;
-      {
-        MDBX_cursor *m2, *m3;
-        MDBX_dbi dbi = mc->mc_dbi;
-
-        for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2 = m2->mc_next) {
-          if (mc->mc_flags & C_SUB)
-            m3 = &m2->mc_xcursor->mx_cursor;
-          else
-            m3 = m2;
-          if (!(m3->mc_flags & C_INITIALIZED) || (m3->mc_snum < mc->mc_snum))
-            continue;
-          if (m3->mc_pg[0] == mp) {
-            m3->mc_snum = 0;
-            m3->mc_top = 0;
-            m3->mc_flags &= ~C_INITIALIZED;
-          }
-        }
-      }
     } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
       int i;
       mdbx_debug("collapsing root page!");