From c5a53dd525123760f7fcd50a1e16662f9a576d19 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=9B=D0=B5=D0=BE=D0=BD=D0=B8=D0=B4=20=D0=AE=D1=80=D1=8C?=
 =?UTF-8?q?=D0=B5=D0=B2=20=28Leonid=20Yuriev=29?= <leo@yuriev.ru>
Date: Sun, 2 Nov 2025 22:12:44 +0300
Subject: [PATCH] mdbx: ending the transaction and return an error in case
 reader-slot was evicted.

---
 src/txn-ro.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/txn-ro.c b/src/txn-ro.c
index bc863329..8e4d8f3d 100644
--- a/src/txn-ro.c
+++ b/src/txn-ro.c
@@ -168,6 +168,15 @@ int txn_ro_end(MDBX_txn *txn, unsigned mode) {
       txn->ro.slot = nullptr;
     else {
       eASSERT(env, slot->pid.weak == env->pid);
+      if (unlikely(slot->pid.weak == 0)) {
+        txn->flags = MDBX_TXN_RDONLY | MDBX_TXN_FINISHED | MDBX_TXN_OUSTED;
+        txn->owner = 0;
+        if (mode & TXN_END_FREE) {
+          txn->signature = 0;
+          osal_free(txn);
+        }
+        return LOG_IFERR(MDBX_BAD_RSLOT);
+      }
       if (likely((txn->flags & MDBX_TXN_FINISHED) == 0)) {
         if (likely((txn->flags & MDBX_TXN_PARKED) == 0)) {
           ENSURE(env, txn->txnid >=