From 2a740d3807b60491a23ab9b1c258ef47d44cad15 Mon Sep 17 00:00:00 2001
From: Leonid Yuriev <leo@yuriev.ru>
Date: Tue, 24 Nov 2020 15:41:08 +0300
Subject: [PATCH] mdbx-windows: fix `ERROR_NOT_SUPPORTED` while opening UNC
 pathnames.

Resolve https://github.com/miranda-ng/miranda-ng/issues/2627

Change-Id: Iec06554dfcb9e0db215662d93fb5824cfe9ac7ef
---
 src/core.c | 4 +++-
 src/osal.c | 6 +++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/core.c b/src/core.c
index 37b8ed19..ab2ef829 100644
--- a/src/core.c
+++ b/src/core.c
@@ -10118,7 +10118,9 @@ static __cold int mdbx_setup_lck(MDBX_env *env, char *lck_pathname,
 
     /* ensure the file system is read-only */
     err = mdbx_check_fs_rdonly(env->me_lazy_fd, lck_pathname, err);
-    if (err != MDBX_SUCCESS)
+    if (err != MDBX_SUCCESS &&
+        /* ignore ERROR_NOT_SUPPORTED for exclusive mode */
+        !(err == MDBX_ENOSYS && (env->me_flags & MDBX_EXCLUSIVE)))
       return err;
 
     /* LY: without-lck mode (e.g. exclusive or on read-only filesystem) */
diff --git a/src/osal.c b/src/osal.c
index 72b19cfd..f263346b 100644
--- a/src/osal.c
+++ b/src/osal.c
@@ -120,6 +120,9 @@ typedef struct _FILE_PROVIDER_EXTERNAL_INFO_V1 {
 #ifndef STATUS_INVALID_DEVICE_REQUEST
 #define STATUS_INVALID_DEVICE_REQUEST ((NTSTATUS)0xC0000010L)
 #endif
+#ifndef STATUS_NOT_SUPPORTED
+#define STATUS_NOT_SUPPORTED ((NTSTATUS)0xC00000BBL)
+#endif
 
 #ifndef FILE_DEVICE_FILE_SYSTEM
 #define FILE_DEVICE_FILE_SYSTEM 0x00000009
@@ -1067,7 +1070,8 @@ static int mdbx_check_fs_local(mdbx_filehandle_t handle, int flags) {
       if (!(flags & MDBX_EXCLUSIVE))
         return ERROR_REMOTE_STORAGE_MEDIA_ERROR;
     } else if (rc != STATUS_OBJECT_NOT_EXTERNALLY_BACKED &&
-               rc != STATUS_INVALID_DEVICE_REQUEST)
+               rc != STATUS_INVALID_DEVICE_REQUEST &&
+               rc != STATUS_NOT_SUPPORTED)
       return ntstatus2errcode(rc);
   }