Fixing bug where duplicate entries could be created when using FileGroup.merge.

wrolpi/files/models.py

@@ -518,14 +518,18 @@ class FileGroup(ModelHelper, Base):
         session = Session.object_session(self)
 
         collected_files = self.files.copy()
+        # Track filenames (strings) for proper deduplication
+        existing_filenames = {f['path'] for f in self.files}
+
         for file_group in file_groups:
             if file_group.primary_path == self.primary_path:
                 # Don't merge myself.
                 continue
 
             for file in file_group.files:
-                if file['path'] not in self.my_paths():
+                if file['path'] not in existing_filenames:
                     collected_files.append(file)
+                    existing_filenames.add(file['path'])  # Track newly added
             # Move any applied Tags.
             for tag_file in file_group.tag_files:
                 if tag_file.tag is not None and tag_file.tag.name not in self.tag_names:

wrolpi/files/test/test_lib.py

@@ -747,6 +747,14 @@ async def test_file_group_merge(async_client, test_session, test_directory, make
     assert vid_group.mimetype == 'video/mp4'
     assert srt_group.mimetype == 'text/srt'
 
+    # Add srt to vid_group so both groups have it (simulates race condition scenario)
+    vid_group.append_files(srt)
+    test_session.commit()
+
+    # Verify both groups have the srt file
+    assert 'vid.srt' in [f['path'] for f in vid_group.files]
+    assert 'vid.srt' in [f['path'] for f in srt_group.files]
+
     # Both FileGroups are merged.
     vid = FileGroup.from_paths(test_session, vid, srt)
     test_session.commit()
@@ -763,6 +771,10 @@ async def test_file_group_merge(async_client, test_session, test_directory, make
     assert vid.size > len(video_bytes)
     assert vid.mimetype == 'video/mp4'
 
+    # Verify no duplicate files were created during merge
+    filenames = [f['path'] for f in vid.files]
+    assert len(filenames) == len(set(filenames)), f"Duplicate files found: {filenames}"
+
 
 @pytest.mark.asyncio
 async def test_move_directory(async_client, test_session, test_directory, make_files_structure,