Comment 3 for bug 207057

Here is what's going from Java's point of view. When user requests clipboard contents, AWT first requests a value of TARGETS atom for CLIPBOARD selection. The code is in XSelection.getFormats():

        XlibWrapper.XConvertSelection(XToolkit.getDisplay(), // X display connection
                getSelectionAtom().getAtom(), // CLIPBOARD atom
                XDataTransferer.TARGETS_ATOM.getAtom(), // TARGETS atom
                selectionPropertyAtom.getAtom(), // "XAWT-SELECTION" atom to fill
                XWindow.getXAWTRootWindow().getWindow(), // requestor window
                time);

The call is successful, and the next thing is to get the value of "XAWT-SELECTION" and convert it to the list of atoms. Here is the list on my linux with synergy client running: 0x189, 0x18a, 0x18b, 0x194, 0xf4, 0x195, 0x196, 0x197, 0x1f, 0x0, 0x14aa1, 0xfffffffff9530698, 0xfffffffff9530698, 0x18a, 0x18b, 0x194, 0xf4, 0x195

Value 0x0 seems odd to me, as well as other repeating values. This only happens when Java and one of synergy clients are started from 64-bit linux, regardless of where synergy server is running.