From f3130152b1b16aa21b73cbb0f0bda69d33a914f3 Mon Sep 17 00:00:00 2001
From: Adrian Sampson <adrian@radbox.org>
Date: Thu, 4 Aug 2011 12:04:22 -0700
Subject: [PATCH] don't count existing items/albums as duplicates (allowing
 update)

---
 beets/importer.py     | 17 ++++++++++++-----
 test/test_importer.py | 40 +++++++++++++++++++++++++++++-----------
 2 files changed, 41 insertions(+), 16 deletions(-)

diff --git a/beets/importer.py b/beets/importer.py
index 1b1cc5ae2..cf60b791a 100644
--- a/beets/importer.py
+++ b/beets/importer.py
@@ -106,8 +106,14 @@ def _duplicate_check(lib, task, recent=None):
         recent.add((artist, album))
 
     # Look in the library.
+    cur_paths = set(i.path for i in task.items)
     for album_cand in lib.albums(artist=artist):
         if album_cand.album == album:
+            # Check whether the album is identical in contents, in which
+            # case it is not a duplicate (will be replaced).
+            other_paths = set(i.path for i in album_cand.items())
+            if other_paths == cur_paths:
+                continue
             return True
 
     return False
@@ -132,13 +138,14 @@ def _item_duplicate_check(lib, task, recent=None):
     # Check the library.
     item_iter = lib.items(artist=artist, title=title)
     try:
-        item_iter.next()
-    except StopIteration:
-        return False
+        for other_item in item_iter:
+            # Existing items not considered duplicates.
+            if other_item.path == task.item.path:
+                continue
+            return True
     finally:
         item_iter.close()
-
-    return True
+    return False
 
 def _infer_album_fields(task):
     """Given an album and an associated import task, massage the
diff --git a/test/test_importer.py b/test/test_importer.py
index 62bcba7f8..15173badc 100644
--- a/test/test_importer.py
+++ b/test/test_importer.py
@@ -434,27 +434,35 @@ class DuplicateCheckTest(unittest.TestCase):
         self.i = _common.item()
         self.album = self.lib.add_album([self.i])
 
-    def _album_task(self, asis, artist=None, album=None):
-        artist = artist or self.i.albumartist
-        album = album or self.i.album
+    def _album_task(self, asis, artist=None, album=None, existing=False):
+        if existing:
+            item = self.i
+        else:
+            item = _common.item()
+        artist = artist or item.albumartist
+        album = album or item.album
 
         task = importer.ImportTask(path='a path', toppath='top path',
-                                   items=[self.i])
+                                   items=[item])
         task.set_match(artist, album, None, None)
         if asis:
             task.set_choice(importer.action.ASIS)
         else:
-            task.set_choice(({'artist': artist, 'album': album}, [self.i]))
+            task.set_choice(({'artist': artist, 'album': album}, [item]))
         return task
 
-    def _item_task(self, asis, artist=None, title=None):
-        artist = artist or self.i.artist
-        title = title or self.i.title
+    def _item_task(self, asis, artist=None, title=None, existing=False):
+        if existing:
+            item = self.i
+        else:
+            item = _common.item()
+        artist = artist or item.artist
+        title = title or item.title
 
-        task = importer.ImportTask.item_task(self.i)
+        task = importer.ImportTask.item_task(item)
         if asis:
-            self.i.artist = artist
-            self.i.title = title
+            item.artist = artist
+            item.title = title
             task.set_choice(importer.action.ASIS)
         else:
             task.set_choice({'artist': artist, 'title': title})
@@ -524,6 +532,16 @@ class DuplicateCheckTest(unittest.TestCase):
                                   recent)
         self.assertTrue(res)
 
+    def test_duplicate_album_existing(self):
+        res = importer._duplicate_check(self.lib,
+                                        self._album_task(False, existing=True))
+        self.assertFalse(res)
+
+    def test_duplicate_item_existing(self):
+        res = importer._item_duplicate_check(self.lib, 
+                                        self._item_task(False, existing=True))
+        self.assertFalse(res)
+
 def suite():
     return unittest.TestLoader().loadTestsFromName(__name__)