(Vim bug?) b:changedtick incremented after undo

[justinmk]

This issue is for reference, I don't have a solution.

At some point Vim changed its b:changedtick behavior after u, to increment more than vim-repeat expects. This can be reproduced with vim-surround, though it also affects vim-sneak.

Steps to reproduce:

$ vim -u NORC -N +":set runtimepath+=~/.vim/bundle/vim-repeat/" +":runtime plugin/repeat.vim" +":set runtimepath+=~/.vim/bundle/vim-surround/" +":runtime plugin/surround.vim"

ifooboo<Esc>0
ystb)
..
u
.

The . after u does not redo the surround operation.

Even though repeat#wrap() preserves g:repeat_tick, b:changedtick is incremented sometime after, so the next . does not work correctly.

[tpope]

No desire to implement it but one fix could be to cache the getchar() result inside opfunc, and clear that cache beforehand when the map is invoked. Then we can ditch the repeat#set() entirely and let . call g@ directly.

[justinmk]

Relaxing the tolerance might be good enough:

diff --git a/autoload/repeat.vim b/autoload/repeat.vim
index ce2141b8753d..7cebc992bbf4 100644
--- a/autoload/repeat.vim
+++ b/autoload/repeat.vim
@@ -75,7 +75,7 @@ endfunction
-
 function! repeat#run(count)
     try
-        if g:repeat_tick == b:changedtick
+        if (b:changedtick - g:repeat_tick <= 2)
             let r = ''
             if g:repeat_reg[0] ==# g:repeat_sequence && !empty(g:repeat_reg[1])
                 if g:repeat_reg[1] ==# '='
@@ -110,7 +110,7 @@ function! repeat#run(count)
 endfunction
-
 function! repeat#wrap(command,count)
-    let preserve = (g:repeat_tick == b:changedtick)
+    let preserve = (b:changedtick - g:repeat_tick <= 2)
     call feedkeys((a:count ? a:count : '').a:command, 'n')
     exe (&foldopen =~# 'undo\|all' ? 'norm! zv' : '')
     if preserve

[tpope]

Is this specific to surround.vim or can it be reproduced with other plugins?

[justinmk]

https://github.com/justinmk/vim-sneak/ is another plugin that is affected by it. My glance at repeat#wrap() leads me to believe this would affect any plugin that uses vim-repeat, since the problem occurs when u is invoked.

[justinmk]

I checked some more plugins which use repeat#set, and confirmed that this issue affects them:

• https://github.com/tommcdo/vim-lion
  • glipa followed by u.
• https://github.com/tpope/vim-unimpaired/
  • [e followed by u.

The hack that I suggested above is too brittle, because the u step may increment b:changedtick by much more than 2 or 3 ticks, e.g. after vim-lion glipa , u increments b:changedtick by 5.

[tpope]

I'll also throw into the mix that a false negative breaking a plugin repeat is probably better than a false positive breaking all built-in repeats.

The direction I am moving is avoid repeat.vim wherever I can in favor of an operator func, even if I have to shoehorn it in. I'm pretty sure I can turn [e into an operator func, for example, and I'll probably do that at some point. Lion can probably use the same trick I proposed for Surround. I'm not sure about operator pending motions though. I don't really have a lot of experience there.

[alexanderak]

Hi!
This solution solves issue:

diff --git a/autoload/repeat.vim b/autoload/repeat.vim
index ce2141b..1a4ab92 100644
--- a/autoload/repeat.vim
+++ b/autoload/repeat.vim
@@ -111,7 +111,7 @@ endfunction
 
 function! repeat#wrap(command,count)
     let preserve = (g:repeat_tick == b:changedtick)
-    call feedkeys((a:count ? a:count : '').a:command, 'n')
+    exe 'norm!' (a:count ? a:count : '').a:command
     exe (&foldopen =~# 'undo\|all' ? 'norm! zv' : '')
     if preserve
         let g:repeat_tick = b:changedtick

[svermeulen]

A plugin I'm working on also suffers from this issue. @alexanderak's patch solves it though. Is there a reason feedkeys needs to be used there instead? If not I hope that can be merged at some point

[svermeulen]

Here's another (possibly lower risk) solution for consideration

diff --git a/autoload/repeat.vim b/autoload/repeat.vim
index ce2141b..c24c872 100644
--- a/autoload/repeat.vim
+++ b/autoload/repeat.vim
@@ -114,7 +114,7 @@ function! repeat#wrap(command,count)
     call feedkeys((a:count ? a:count : '').a:command, 'n')
     exe (&foldopen =~# 'undo\|all' ? 'norm! zv' : '')
     if preserve
-        let g:repeat_tick = b:changedtick
+        call feedkeys(":let g:repeat_tick = b:changedtick\<cr>", 'n')
     endif
 endfunction