更新
20171215
该问题同鼠标右键单击不能粘贴。

升级到debian 9后，出现了在Chromebook的Secure Shell中双击触摸板不能在VIM中粘贴的问题，Chromebook中Secure Shell中双击触摸板类似于鼠标右键的操作。问题表现为：双击触摸板时，变成了— (insert) VISUAL —模式，粘贴失效。
解决办法：将 set mouse=a 改为set mouse=r。
具体如下：

vi /usr/share/vim/vim80/defaults.vim

将
" In many terminal emulators the mouse works just fine.  By enabling it you
" can position the cursor, Visually select and scroll with the mouse.
if has('mouse')
  set mouse=a
endif

改为：

" In many terminal emulators the mouse works just fine.  By enabling it you
" can position the cursor, Visually select and scroll with the mouse.
if has('mouse')
  set mouse=r
endif