From 7a829f484afda16992326f3bb7080a8cd6b1d0a9 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 7 Jan 2023 13:39:35 +0530
Subject: [PATCH] Windows MTP device driver: Ignore failure to enumerate
 objects inside non-root folders

There are apparently a lot of devices out there that fail in this way.
So rather than aborting the scan simply ignore the folder.
---
 src/calibre/devices/mtp/windows/content_enumeration.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/calibre/devices/mtp/windows/content_enumeration.cpp b/src/calibre/devices/mtp/windows/content_enumeration.cpp
index 411d5dc210..3c1b8503eb 100644
--- a/src/calibre/devices/mtp/windows/content_enumeration.cpp
+++ b/src/calibre/devices/mtp/windows/content_enumeration.cpp
@@ -320,6 +320,7 @@ find_objects_in(CComPtr<IPortableDeviceContent> &content, CComPtr<IPortableDevic
      */
     CComPtr<IEnumPortableDeviceObjectIDs> children;
     HRESULT hr = S_OK, hr2 = S_OK;
+    *enum_failed = false;
 
     Py_BEGIN_ALLOW_THREADS;
     hr = content->EnumObjects(0, parent_id, NULL, &children);
@@ -338,7 +339,6 @@ find_objects_in(CComPtr<IPortableDeviceContent> &content, CComPtr<IPortableDevic
             return false;
         }
     }
-    *enum_failed = false;
 
     hr = S_OK;
 
@@ -464,7 +464,11 @@ get_files_and_folders(unsigned int level, IPortableDevice *device, CComPtr<IPort
 
     bool enum_failed = false;
     if (!find_objects_in(content, object_ids, parent_id, &enum_failed)) {
-        return false;
+        // There are quite a few devices where EnumObjects fails for some folders, so unless it is the root folder ignore the failure.
+        if (!enum_failed || !level) return false;
+        PyErr_Print();
+        fwprintf(stderr, L"Ignoring failure of EnumObjects() at level %u\n", level); fflush(stderr);
+        return true;
     }
 
     if (bulk_properties != NULL) {