Tab keep triggering jump backward in ultisnips

Question

I have a problem with UltiSnips. It keeps jump backwards even tough I didn't map it in my .vimrc file. My .vimrc look like this

let g:UltiSnipsExpandTrigger="<C-l>"                                             
let g:UltiSnipsJumpForwardTrigger="<C-k>"                                        
let g:UltiSnipsJumpBackwardTrigger="<C-i>"

let g:ycm_key_list_select_completion = ['<Tab>', '<Down>']                       
let g:ycm_key_list_previous_completion = ['<S-Tab>', '<Up>']                     

let g:SuperTabDefaultCompletionType = '<Tab>' 

No there saying anything about <Tab> executing JumpBackwardTrigger. But, when type this:

fpri                             \\ Then hit <tab>, it expands to:
fprintf(stderr, "%s\n", str__);  \\ My cursor at __. YCM need to do the job
                                 \\ when I start typing. Then I hit <tab>
fprintf(stderr, "__\n", str);    \\ But it bring back!!

I have no mapping that involves <tab> key. So, what is causing this?

Answer 1

Unfortunately <c-i> and <tab> are parsed as the exact same key by most terminals. You can follow a discussion about this on this neovim issue: https://github.com/neovim/neovim/issues/176

The easiest solution is to pick a different mapping for jumping backwards, like <leader>i. If you really want this fixed, I suggest following the linked issue and looking into leonerd's work.