guioptions+=!, sighup and hit-enter with system()

[lilydjwg]

There are two issues that has been with me for a long time.

The first: hit-enter after calling system().

1. gvim --clean to start
2. set go=acit! (I don't know the exact conbinations for the issue to occur yet.)
3. let a = system('ls'), and you'll get a "hit-enter" prompt.

This is a blocker issue for vim-racer, because this completer will call system() to get completions, and "hit-enter"s break typing. Sometimes I see a "^R" line shown after pressing enter.

The second: SIGHUP for background commands.

1. gvim --clean to start
2. set go+=!
3. call system("firefox https://www.vim.org/ &")
4. Nothing happens. The firefox process was killed by SIGHUP. Even I prefix it with nohup, nohup itself was killed before it fully set itself up.

Vim version 8.1.278 huge build with gtk2 GUI, on Arch Linux.

Full `--version` output

VIM - Vi IMproved 8.1 (2018 May 18, compiled Aug 13 2018 02:50:50)
Included patches: 1-278
Modified by me
Compiled by me@mymachine
Huge version with GTK2 GUI.  Features included (+) or not (-):
+acl               +extra_search      +mouse_netterm     +tag_old_static
+arabic            +farsi             +mouse_sgr         -tag_any_white
+autocmd           +file_in_path      -mouse_sysmouse    -tcl
+autochdir         +find_in_path      +mouse_urxvt       +termguicolors
-autoservername    +float             +mouse_xterm       +terminal
+balloon_eval      +folding           +multi_byte        +terminfo
+balloon_eval_term -footer            +multi_lang        +termresponse
+browse            +fork()            -mzscheme          +textobjects
++builtin_terms    +gettext           +netbeans_intg     +timers
+byte_offset       -hangul_input      +num64             +title
+channel           +iconv             +packages          +toolbar
+cindent           +insert_expand     +path_extra        +user_commands
+clientserver      +job               +perl/dyn          +vartabs
+clipboard         +jumplist          +persistent_undo   +vertsplit
+cmdline_compl     +keymap            +postscript        +virtualedit
+cmdline_hist      +lambda            +printer           +visual
+cmdline_info      +langmap           +profile           +visualextra
+comments          +libcall           +python/dyn        +viminfo
+conceal           +linebreak         +python3/dyn       +vreplace
+cryptv            +lispindent        +quickfix          +wildignore
+cscope            +listcmds          +reltime           +wildmenu
+cursorbind        +localmap          +rightleft         +windows
+cursorshape       +lua/dyn           +ruby/dyn          +writebackup
+dialog_con_gui    +menu              +scrollbind        +X11
+diff              +mksession         +signs             -xfontset
+digraphs          +modify_fname      +smartindent       +xim
+dnd               +mouse             +startuptime       -xpm
-ebcdic            +mouseshape        +statusline        +xsmp_interact
+emacs_tags        +mouse_dec         -sun_workshop      +xterm_clipboard
+eval              +mouse_gpm         +syntax            -xterm_save
+ex_extra          -mouse_jsbterm     +tag_binary        
   system vimrc file: "$VIM/vimrc"
     user vimrc file: "$HOME/.vimrc"
 2nd user vimrc file: "~/.vim/vimrc"
      user exrc file: "$HOME/.exrc"
  system gvimrc file: "$VIM/gvimrc"
    user gvimrc file: "$HOME/.gvimrc"
2nd user gvimrc file: "~/.vim/gvimrc"
       defaults file: "$VIMRUNTIME/defaults.vim"
    system menu file: "$VIMRUNTIME/menu.vim"
  fall-back for $VIM: "/usr/share/vim"
Compilation: gcc -c -I. -Iproto -DHAVE_CONFIG_H -DFEAT_GUI_GTK  -I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include -I/usr/include/pango-1.0 -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/fribidi -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/harfbuzz -I/usr/include/uuid -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/atk-1.0 -pthread  -D_FORTIFY_SOURCE=2  -g -O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1       
Linking: gcc   -L. -Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now -fstack-protector -rdynamic -Wl,-export-dynamic -Wl,-E -Wl,-rpath,/usr/lib/perl5/5.28/core_perl/CORE  -Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now -L/usr/local/lib -Wl,--as-needed -o vim   -lgtk-x11-2.0 -lgdk-x11-2.0 -lpangocairo-1.0 -latk-1.0 -lcairo -lgdk_pixbuf-2.0 -lgio-2.0 -lpangoft2-1.0 -lpango-1.0 -lgobject-2.0 -lglib-2.0 -lfontconfig -lfreetype  -lSM -lICE -lXt -lX11 -lXdmcp -lSM -lICE  -lm -ltinfo -lelf -lnsl    -lacl -lattr -lgpm -ldl   -Wl,-E -Wl,-rpath,/usr/lib/perl5/5.28/core_perl/CORE -Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now -fstack-protector-strong -L/usr/local/lib  -L/usr/lib/perl5/5.28/core_perl/CORE -lperl -lpthread -ldl -lm -lcrypt -lutil -lc        

[lifepillar]

The first: hit-enter after calling system().

How about:

silent let a = system('ls')

[lilydjwg]

silent does prevent the hit-enter prompt. But it means I have to patch (potentially a lot of) 3rd party plugins.

[chdiza]

The first issue happens in MacVim too, FYI.

[chrisbra]

I had a look. It happens because do_cmdline() is called recursively. BTW: I noticed that a bunch of autocommands are executed when using :set guioptions+=! like BufAdd, BufEnter, and then WinLeave, BufDelete. I think we could skip those at least for system().

Thinking a bit more about the system() case, is there a reason, we don't simply set no_wait_return when executing the system() function? At least in that case we don't expect any output to be displayed directly, right?

[brammool]

Christian wrote:

I had a look. It happens because do_cmdline() is called recursively. BTW: I noticed that a bunch of autocommands are executed when using `:set guioptions+=!` like BufAdd, BufEnter, and then WinLeave, BufDelete. I think we could skip those at least for `system()`. Thinking a bit more about the `system()` case, is there a reason, we don't simply set `no_wait_return` when executing the system() function? At least in that case we don't expect any output to be displayed directly, right?

If system() doesn't output anything, why does setting no_wait_return make any difference?

…

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[chrisbra]

I suppose that comes from the output in the (hidden) terminal window.

[lixiao-t4f]

vim/src/os_unix.c

Line 5477 in 7db3a8e

if (gui.in_use && vim_strchr(p_go, GO_TERMINAL) != NULL)

I guess this is where system() is affected by 'go-!'.

If so, what about always skipping terminal for system()? Since system() is not meant to be used interactively, an interactive terminal is not needed.

I go into this issue, since I have autocmd defined in InsertLeavePre, which calls system(), fails when in cmdwin; I think lilydjwg's fcitx.vim plugin is also affected by this issue.

MRE: in command mode, press <C-f> to enter cmdwin, then press i to enter cmdwin insert mode and press <Esc> to leave. E1188 (open terminal fail) and E282 (read tempfile fail) will be trigger.

[lixiao-t4f]

E282 is raised, maybe because I define related function / autocmd in my vimrc. Sorry for the incorrect comment.

Also, E1188 is more about command-line window, not terminal window.