Fix maximum clipboard size for protocol 1.8

After revising the header files and definitions, conditions required
readjusting to support clipboard sizes over 65000 up to 320000

gui-agent/vmside.c

@@ -985,18 +985,15 @@ static void send_clipboard_data(libvchan_t *vchan, XID window, char *data, uint3
     struct msg_hdr hdr;
     hdr.type = MSG_CLIPBOARD_DATA;
     hdr.window = window;
-    if (len > MAX_CLIPBOARD_SIZE)
-    {
-        if (protocol_version >= QUBES_GUID_MIN_CLIPBOARD_4X) {
-            // xside is capable of receiving (up to) 4X of the previous size.
-            // it is also smarter. send one byte over the new buffer limit.
-            // A simple sign for xside to reject it.
-            len = MAX_CLIPBOARD_BUFFER_SIZE + 1;
-        } else {
-            // The dumb case. Truncate the data to the old size. User will lose
-            // some inter-vm clipboard data without being notified.
-            len = MAX_CLIPBOARD_SIZE;
-        }
+    if ((protocol_version < QUBES_GUID_MIN_CLIPBOARD_4X) && (len > MAX_CLIPBOARD_SIZE)) {
+        // The dumb case. Truncate the data to the old size. User might lose
+        // some inter-vm clipboard data without being notified.
+        len = MAX_CLIPBOARD_SIZE;
+    } else if (len > MAX_CLIPBOARD_BUFFER_SIZE + 1) {
+        // xside is capable of receiving (up to) 4X of the previous size.
+        // it is also smarter. send one byte over the new buffer limit.
+        // A simple sign for xside to reject it.
+        len = MAX_CLIPBOARD_BUFFER_SIZE + 1;
     }
     hdr.untrusted_len = len;
     write_struct(vchan, hdr);
@@ -1063,9 +1060,9 @@ static void process_xevent_selection(Ghandles * g, XSelectionEvent * ev)
     else
         if (type == XInternAtom(g->display, "INCR", False)) {
             char INCR_WARNING[] =
-                "Qube clipboard size over 256KiB and X11 INCR protocol support is not implemented!\n";
+                "Qube clipboard size over 256KiB and X11 INCR protocol support is not implemented!";
             send_clipboard_data(g->vchan, g->stub_win, (char *) &INCR_WARNING,
-                                sizeof(INCR_WARNING), g->protocol_version);
+                                sizeof(INCR_WARNING)-1, g->protocol_version);
         } else {
             send_clipboard_data(g->vchan, g->stub_win, (char *) data, len,
                                 g->protocol_version);