Eu vejo duas soluções:
- você teria que testar o destaque da sintaxe atual para pular para a parte vermelha na linha.
- você teria que extrair a linha atual nos dois buffers e encontrar o primeiro caractere que difere para posicionar corretamente o cursor
Ambas as soluções precisam ser executadas após o] c e requerem o script vim.
EDITAR: Aqui está um primeiro rascunho que parece funcionar:
nnoremap <expr> <silent> <F3> (&diff ? "]c:call \<sid>NextDiff()\<cr>" : ":cn\<cr>")
function! s:GotoWinline(w_l)
normal! H
while winline() < a:w_l
normal! j
endwhile
" todo: beware of cases where the window is too little
endfunction
" Better ]c, [c jump
function! s:NextDiff()
if ! &diffopt =~ 'filler' | return | endif
let ignore_blanks = &diffopt =~ 'iwhite'
" Assert: called just after a ]c or a [c
" Forces the cursos to be synchronized in all synced windows
" let diff_l = line()
try
let foldenable = &foldenable
set nofoldenable
let w_l = winline() " problematic with enabled lines (from diff...)
" echomsg w_l.'|'.line('.').'|'.getline('.')
let lines = {}
windo if &diff | call <sid>GotoWinline(w_l) | let lines[winnr()]={'text':getline('.'), 'number':line('.')} | endif
finally
let &foldenable = foldenable
endtry
" echomsg string(lines)
if len(lines) < 2 | return | endif
let indices = repeat([0], len(lines))
let tLines = values(lines)
let found = 0
" infinite loop on two empty texts...
while ! found
let c = ''
let next_idx = []
let i = 0
while i != len(indices)
let crt_line = tLines[i].text
let n = indices[i]
if len(crt_line) == n
let found = 1
break
endif
let c2 = (len(crt_line) == n) ? 'EOL' : crt_line[n]
if empty(c)
let c = c2
endif
" checks match
let n += 1
if c =~ '\s'
if (c2 != c) && (ignore_blanks && c2 !~ '\s')
let found = 1
break
else " advance
while ignore_blanks && (n == len(crt_line) || crt_line[n] =~ '\s')
let n += 1
endwhile
endif
else
if c2 != c
let found = 1
break
endif
endif
let next_idx += [n]
let i += 1
endwhile
if found | break | endif
let indices = next_idx
endwhile
" now goto the right column
let windows = keys(lines)
" Assert len(windows) == len(indices)
let w = 0
while w != len(windows)
" echomsg 'W#'.windows[w].' -> :'(tLines[w].number).'normal! '.(indices[w]+1).'|'
exe windows[w].'wincmd w'
silent! exe (tLines[w].number).'normal! 0'.(indices[w]).'l'
let w += 1
endwhile
" echomsg string(indices)
endfunction