Applications using ole32's clipboard API (e.g. Radeon / QT5) end up monitoring the content of the clipboard and calling OpenClipboard() while user32:clipboard runs. This causes the test's own OpenClipboard() calls to fail. Similarly the KDE clipboard manager may query the Wine clipboard content while the test runs, causing winex11.drv to call OpenClipboard() with the same effect. So call OpenClipboard() again when it fails due to the clipboard already being open. If opening the clipboard still fails, trace who opened the clipboard, particularly the window class name to help identify the source of interference. Signed-off-by: Francois Gouget <fgouget@codeweavers.com> Signed-off-by: Alexandre Julliard <julliard@winehq.org>