Open Radar

 
Summary:

If any application is monitoring the pasteboard, and if the Finder is used to "Copy" a large number of items, and if the monitoring of the pasteboard happens while the Finder is populating the pasteboard, files will be missed.  When pasted, some files will be missing.

Steps to Reproduce:

Install any clipboard history application (eg Keyboard Maestro, iClip, PTH Pasteboard, etc).
Create a directory with a large number of small files in it (1000-100,000).
Create a new empty directory.
Select Al files in the first folder.
Command-C
Move to the second folder
Command-V

Expected Results:

All files copied.

Actual Results:

Some files are missed if the pasteboard is read while the Finder is populating the pasteboard.

Notes:

This may be a bug in the Finder, or a bug in the system pasteboard.  There is no apparent way to set the clipboard atomically, nor to tell when a change to the clipboard is "completed".

If the reading clipboard accesses [[NSPasteboard generalPasteboard] changeCount] and either  [[[NSPasteboard generalPasteboard] pasteboardItems] count] or PasteboardGetItemCount, files will be lost.