...

src/calibre/devices/mtp/filesystem_cache.py

@@ -8,6 +8,7 @@
 __docformat__ = 'restructuredtext en'
 
 import weakref, sys
+from collections import deque
 from operator import attrgetter
 from future_builtins import map
 
@@ -50,6 +51,16 @@ def id_map(self):
     def parent(self):
         return None if self.parent_id is None else self.id_map[self.parent_id]
 
+    @property
+    def full_path(self):
+        parts = deque()
+        parts.append(self.name)
+        p = self.parent
+        while p is not None:
+            parts.appendleft(p.name)
+            p = p.parent
+        return tuple(parts)
+
     def __iter__(self):
         for e in self.folders:
             yield e

src/calibre/devices/mtp/windows/driver.py

@@ -15,7 +15,7 @@
 from calibre import as_unicode, prints
 from calibre.constants import plugins, __appname__, numeric_version
 from calibre.ptempfile import SpooledTemporaryFile
-from calibre.devices.errors import OpenFailed
+from calibre.devices.errors import OpenFailed, DeviceError
 from calibre.devices.mtp.base import MTPDeviceBase
 from calibre.devices.mtp.filesystem_cache import FilesystemCache
 
@@ -245,13 +245,20 @@ def free_space(self, end_session=True):
 
     @same_thread
     def get_file(self, object_id, stream=None, callback=None):
+        f = self.filesystem_cache.id_map[object_id]
+        if f.is_folder:
+            raise ValueError('%s is a folder on the device'%f.full_path)
         if stream is None:
             stream = SpooledTemporaryFile(5*1024*1024, '_wpd_receive_file.dat')
         try:
-            self.dev.get_file(object_id, stream, callback)
-        except self.wpd.WPDFileBusy:
-            time.sleep(2)
-            self.dev.get_file(object_id, stream, callback)
+            try:
+                self.dev.get_file(object_id, stream, callback)
+            except self.wpd.WPDFileBusy:
+                time.sleep(2)
+                self.dev.get_file(object_id, stream, callback)
+        except Exception as e:
+            raise DeviceError('Failed to fetch the file %s with error: %s'%
+                    f.full_path, as_unicode(e))
         return stream
 
     @same_thread