better condition on recommendation

Author: thaerkh

README.md

@@ -3,11 +3,11 @@
 ```
 ```vim
 " Feel free to use this alternative to the plugin's core autosave and session management features:
-au BufLeave,CursorHold,CursorHoldi,FocusLost * if (&buftype == '') | do BufWritePre | silent! update | do BufWritePost | endif
-au VimEnter * nested if (len(v:argv) == 1) | silent! source Session.vim | mksession! | endif
+au BufLeave,CursorHold,FocusLost * if(getbufinfo('%')[0].changed) | do BufWritePre | sil! up | do BufWritePost | endif
+au VimEnter * nested if (len(v:argv) == 1) | silent! source Session.vim | endif
 au VimLeave * if (len(v:argv) == 1) | mksession! | endif
+" available since v8.1.2233 (2019-10-28), v:argv doubles for both stdin and argful cases (instead of argc() and a StdinReadPre autocmd flag)
 " v:argv length check may need to be 2 if using Neovim since it includes an --embed argument on launch
-" v:argv doubles for both stdin and argful cases (instead of argc() and a StdinReadPre autocmd flag)
 ```
 ---
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