Problem with folds

[hcgraf]

Hi,

when working with this (btw. very great) plugin and very big files, I found the following bug:
Because my blocks to compare are very long, it's convenient to fold them first and then do the Linediff.
That causes Linediff to remove the end of the file (i.e. after the second block).

I'll do a step by step example:

• Open vim with an empty buffer. Type / paste the following code:

def one
  two
end

def two
  three
end

something at the end of the file

• Fold the two blocks of codes (vim ex commands):

:1,3fold
:5,7fold

• Select each block for Linediff (the cool thing is, this works with V on the closed fold!):

:1,3Linediff
:5,7Linediff

• Change something in the second (right) diff-buffer, and save it

Result (at least for me):

• The change is correctly copied to the original buffer (that's good)
• The fold is gone (that's not perfect but ok)
• The text after the second fold is gone (that's the bug ;-) )

[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.