Problem with folds about linediff.vim

[AndrewRadev]

Thank you for the detailed bug report, I really appreciate the example.

Unfortunately, I can't seem to reproduce the issue :/. My guess is that there's some setting that I have that's making the difference. Could you show me your .vimrc? I might be able to find the setting like that. Let me know what your Vim version is as well, just in case.

[hcgraf]

Thank you for your fast reply!
You're right, with a minimal vimrc, it doesn't occur.
My vimrc is quite big and a lot of plugins, so I don't want you to work through all of that ;)
I'll do my own investigations and I'll report back if I find the culprit!

Thanks anyway!

[AndrewRadev]

It's likely that it's a setting and not a plugin, because i can't think of any plugin that could affect this one. If you manage to narrow it down to whatever setting is causing this, do let me know. There might be something I could do on the plugin side to prevent people from being affected by it.

[hcgraf]

Ok, I think I tracked it down, it was quite a tough one ;)

It happens only if

• Nerd-Tree-Tabs plugin is enabled (https://github.com/jistr/vim-nerdtree-tabs)
• The Nerd-Tree is open when starting the linediff

The Nerd-Tree-Tabs plugin which tries to make a NerdTree buffer persistent over all tabs. It's probably a quite hacky abuse of the way vim handles buffers/tabs, so that's probably the reason it interferes here :(

OK, at least I have a workaround now (just close Nerdtree).
But of course, if you want to have a closer look at it and find a proper solution (or maybe a bug in NerdtreeTabs), that would be even better :)

[hcgraf]

OK now again with automatic testcase with minimal vimrc, so it should be reproducible independently of the environment.

• download / clone linediff, nerdtree, nerdtree-tabs to ~/.vim/bundle/
• create a new folder with three files:

vimrc

set nocompatible
filetype off
set runtimepath=~/.vim/bundle/linediff.vim/
set runtimepath^=~/.vim/bundle/nerdtree/
set runtimepath^=~/.vim/bundle/vim-nerdtree-tabs/
filetype plugin indent on 

test.txt

def one
  two
end

def two
  three
end

something at the end of the file

script.vim

NERDTreeTabsOpen
" move the cursor out of the NERDTree buffer
winc l
1,3fold
5,7fold
1,3Linediff
5,7Linediff
" change something in the right diff buffer
winc l
normal ciwabc
w
" back to the original test.txt buffer
normal gt
/something

• run the command in this folder: vim -u vimrc test.txt -c 'source script.vim'

You have reproduced the bug, if you get an error message saying that 'something' was not found.
By commenting the first line in script.vim 'something' is found.

[AndrewRadev]

Okay, I've managed to reproduce it, and I think the key is the setting g:nerdtree_tabs_synchronize_focus. If I set it to 0, the issue doesn't seem to happen. My guess is that, when I switch around buffers, an autocommand catches the event and switches to the NERDTree instead. I can't really think of how I could fix this on my end, to be honest, but if this setting works, it might be the simplest way to avoid this happening.

[xaizek]

@AndrewRadev, see :help autocmd-disable. There are 'eventignore' and :noautocmd. Sounds like they might be useful here.

[AndrewRadev]

Thanks, @xaizek, it might be something to experiment with. I'm not sure it'll work, since I think it's autocommands that get triggered outside the plugin that do this. Still, it's something to try.