fix import deletion race

By moving the duplicate file removal to the manipulate_files coroutine, we
ensure that all previous albums are fully moved/copied before trying to delete
their duplicate files.

Author: sampsyo

beets/importer.py

@@ -768,13 +768,12 @@ def apply_choices(session):
 
             # Delete duplicate files that are located inside the library
             # directory.
+            task.duplicate_paths = []
             for duplicate_path in [i.path for i in duplicate_items]:
                 if session.lib.directory in util.ancestry(duplicate_path):
-                    log.debug(u'deleting replaced duplicate %s' %
-                              util.displayable_path(duplicate_path))
-                    util.remove(duplicate_path)
-                    util.prune_dirs(os.path.dirname(duplicate_path),
-                                    session.lib.directory)
+                    # Mark the path for deletion in the manipulate_files
+                    # stage.
+                    task.duplicate_paths.append(duplicate_path)
 
         # Add items -- before path changes -- to the library. We add the
         # items now (rather than at the end) so that album structures
@@ -823,6 +822,15 @@ def manipulate_files(session):
         if task.should_skip():
             continue
 
+        # Remove duplicate files marked for deletion.
+        if task.remove_duplicates:
+            for duplicate_path in task.duplicate_paths:
+                log.debug(u'deleting replaced duplicate %s' %
+                          util.displayable_path(duplicate_path))
+                util.remove(duplicate_path)
+                util.prune_dirs(os.path.dirname(duplicate_path),
+                                session.lib.directory)
+
         # Move/copy/write files.
         items = task.imported_items()
         task.old_paths = [item.path for item in items]  # For deletion.

docs/changelog.rst

@@ -14,6 +14,11 @@ Changelog
 * :doc:`/plugins/fetchart`: Look for images in the Cover Art Archive for
   the release group in addition to the specific release. Thanks to Filipe
   Fortes.
+* Fix a race in the importer that could cause files to be deleted before they
+  were imported. This happened when importing one album, importing a duplicate
+  album, and then asking for the first album to be replaced with the second.
+  The situation could only arise when importing music from the library
+  directory and when the two albums are imported close in time.
 
 
 1.2.1 (June 22, 2013)