From 45f8197635e4f949c58155173b8c2cb138fb48e5 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: Thu, 24 Mar 2022 00:19:34 +0300
Subject: [PATCH] mdbx: clarify/refine error messages of a signature/version
 mismatch.

---
 src/core.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/core.c b/src/core.c
index 82fd1405..4ed205ec 100644
--- a/src/core.c
+++ b/src/core.c
@@ -12524,14 +12524,19 @@ __cold static int mdbx_setup_lck(MDBX_env *env, char *lck_pathname,
     }
   } else {
     if (lck->mti_magic_and_version != MDBX_LOCK_MAGIC) {
-      mdbx_error("%s", "lock region has invalid magic/version");
-      err = ((lck->mti_magic_and_version >> 8) != MDBX_MAGIC)
-                ? MDBX_INVALID
-                : MDBX_VERSION_MISMATCH;
+      const bool invalid = (lck->mti_magic_and_version >> 8) != MDBX_MAGIC;
+      mdbx_error(
+          "lock region has %s",
+          invalid
+              ? "invalid magic"
+              : "incompatible version (only applications with nearly or the "
+                "same versions of libmdbx can share the same database)");
+      err = invalid ? MDBX_INVALID : MDBX_VERSION_MISMATCH;
       goto bailout;
     }
     if (lck->mti_os_and_format != MDBX_LOCK_FORMAT) {
-      mdbx_error("lock region has os/format 0x%" PRIx32 ", expected 0x%" PRIx32,
+      mdbx_error("lock region has os/format signature 0x%" PRIx32
+                 ", expected 0x%" PRIx32,
                  lck->mti_os_and_format, MDBX_LOCK_FORMAT);
       err = MDBX_VERSION_MISMATCH;
       goto bailout;