Fix string overrun in copy-to-clipboard
Fix string overrun in copy-to-clipboard

Check return value and set the terminating zero when copying the string
to clipboard.

momodalo/vimtouch,dnkalpesh/vimtouch,dnkalpesh/vimtouch,dnkalpesh/vimtouch,dnkalpesh/vimtouch,momodalo/vimtouch,momodalo/vimtouch,dnkalpesh/vimtouch,momodalo/vimtouch