feat(client): add Vim split/tab/back link-follow commands + true tab-drop

The plain-Vim client only defined VimwikiFollowLink; the split/vsplit/
tabnew/tabdrop/back command surface existed only in the Neovim branch.
Add :Vimwiki{Split,VSplit,Tabnew,TabDrop,GoBack}Link (+ :Nuwiki* aliases)
to the Vim branch, backed by a new nuwiki#commands#follow_link_drop()
helper that runs `:tab drop` to reuse an already-open tab.

Both clients now implement real tab-drop: open_uri gains a 'tabdrop'
case and M.follow_link_drop(); the Neovim TabDropLink commands and the
<C-S-CR> mappings (Vim + Lua) are repointed off the old tabnew cheat.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

autoload/nuwiki/commands.vim

@@ -188,6 +188,47 @@ function! s:badd_from_response(notification) abort
   echom 'nuwiki: added ' . l:path
 endfunction
 
+" `:VimwikiTabDropLink` — open the link target in a tab, reusing an
+" existing tab/window if the file is already shown (`:tab drop`). Routes
+" through vim-lsp's textDocument/definition like `badd_link`.
+function! nuwiki#commands#follow_link_drop() abort
+  if s:has_vimlsp()
+    call lsp#send_request(s:server, {
+          \ 'method': 'textDocument/definition',
+          \ 'params': s:cursor_position(),
+          \ 'on_notification': function('s:drop_from_response'),
+          \ })
+    return
+  endif
+  if s:has_coc()
+    let l:locs = CocAction('getDefinition')
+    if type(l:locs) == type([]) && !empty(l:locs)
+      let l:uri = get(l:locs[0], 'uri', get(l:locs[0], 'targetUri', ''))
+      if !empty(l:uri)
+        let l:path = substitute(l:uri, '^file://', '', '')
+        execute 'tab drop ' . fnameescape(l:path)
+      endif
+    endif
+    return
+  endif
+  echohl ErrorMsg | echom 'nuwiki: no supported LSP client for follow_link_drop' | echohl None
+endfunction
+
+function! s:drop_from_response(notification) abort
+  let l:result = get(get(a:notification, 'response', {}), 'result', {})
+  let l:uri = ''
+  if type(l:result) == type({})
+    let l:uri = get(l:result, 'uri', get(l:result, 'targetUri', ''))
+  elseif type(l:result) == type([]) && !empty(l:result)
+    let l:uri = get(l:result[0], 'uri', get(l:result[0], 'targetUri', ''))
+  endif
+  if l:uri ==# ''
+    return
+  endif
+  let l:path = substitute(l:uri, '^file://', '', '')
+  execute 'tab drop ' . fnameescape(l:path)
+endfunction
+
 " ===== Smart <CR>: follow or wrap-then-follow =====
 
 function! s:cursor_inside_wikilink() abort

ftplugin/vimwiki.vim

@@ -47,6 +47,11 @@ if !has('nvim')
   command! -buffer        VimwikiDiaryPrevDay           call nuwiki#commands#diary_prev()
   command! -buffer        VimwikiDiaryGenerateLinks     call nuwiki#commands#diary_generate_index()
   command! -buffer        VimwikiFollowLink             call nuwiki#commands#follow_link_or_create()
+  command! -buffer        VimwikiSplitLink              split  | call nuwiki#commands#follow_link_or_create()
+  command! -buffer        VimwikiVSplitLink             vsplit | call nuwiki#commands#follow_link_or_create()
+  command! -buffer        VimwikiTabnewLink            tabnew | call nuwiki#commands#follow_link_or_create()
+  command! -buffer        VimwikiTabDropLink           call nuwiki#commands#follow_link_drop()
+  command! -buffer        VimwikiGoBackLink            execute "normal! \<C-o>"
   command! -buffer        VimwikiBacklinks              call nuwiki#commands#backlinks()
   command! -buffer        VWB                           call nuwiki#commands#backlinks()
   command! -buffer        VimwikiNextLink               call nuwiki#commands#link_next()
@@ -113,6 +118,11 @@ if !has('nvim')
   command! -buffer        NuwikiDiaryNext      call nuwiki#commands#diary_next()
   command! -buffer        NuwikiDiaryPrev      call nuwiki#commands#diary_prev()
   command! -buffer        NuwikiFollowLink call nuwiki#commands#follow_link_or_create()
+  command! -buffer        NuwikiSplitLink  split  | call nuwiki#commands#follow_link_or_create()
+  command! -buffer        NuwikiVSplitLink vsplit | call nuwiki#commands#follow_link_or_create()
+  command! -buffer        NuwikiTabnewLink tabnew | call nuwiki#commands#follow_link_or_create()
+  command! -buffer        NuwikiTabDropLink call nuwiki#commands#follow_link_drop()
+  command! -buffer        NuwikiGoBackLink execute "normal! \<C-o>"
   command! -buffer        NuwikiBacklinks  call nuwiki#commands#backlinks()
   command! -buffer        NuwikiDeleteFile call nuwiki#commands#delete_file()
   command! -buffer        NuwikiRenameFile call nuwiki#commands#rename_file()
@@ -196,7 +206,7 @@ if !has('nvim')
       nnoremap <silent><buffer> <CR>       :call nuwiki#commands#follow_link_or_create()<CR>
       nnoremap <silent><buffer> <S-CR>     :split<CR>:call nuwiki#commands#follow_link_or_create()<CR>
       nnoremap <silent><buffer> <C-CR>     :vsplit<CR>:call nuwiki#commands#follow_link_or_create()<CR>
-      nnoremap <silent><buffer> <C-S-CR>   :tabnew<CR>:call nuwiki#commands#follow_link_or_create()<CR>
+      nnoremap <silent><buffer> <C-S-CR>   :call nuwiki#commands#follow_link_drop()<CR>
       nnoremap <silent><buffer> <BS>       <C-o>
       nnoremap <silent><buffer> <Tab>      /\[\[<CR>:nohlsearch<CR>
       nnoremap <silent><buffer> <S-Tab>    ?\[\[<CR>:nohlsearch<CR>
@@ -357,7 +367,7 @@ command! -buffer        VimwikiGoBackLink  execute "normal! \<C-o>"
 command! -buffer        VimwikiSplitLink   split | lua vim.lsp.buf.definition()
 command! -buffer        VimwikiVSplitLink  vsplit | lua vim.lsp.buf.definition()
 command! -buffer        VimwikiTabnewLink  tabnew | lua vim.lsp.buf.definition()
-command! -buffer        VimwikiTabDropLink tabnew | lua vim.lsp.buf.definition()
+command! -buffer        VimwikiTabDropLink lua require('nuwiki.commands').follow_link_drop()
 command! -buffer        VimwikiNextLink    lua require('nuwiki.commands').link_next()
 command! -buffer        VimwikiPrevLink    lua require('nuwiki.commands').link_prev()
 command! -buffer        VimwikiBaddLink    lua require('nuwiki.commands').badd_link()
@@ -465,7 +475,7 @@ command! -buffer        NuwikiGoBackLink  execute "normal! \<C-o>"
 command! -buffer        NuwikiSplitLink   split | lua vim.lsp.buf.definition()
 command! -buffer        NuwikiVSplitLink  vsplit | lua vim.lsp.buf.definition()
 command! -buffer        NuwikiTabnewLink  tabnew | lua vim.lsp.buf.definition()
-command! -buffer        NuwikiTabDropLink tabnew | lua vim.lsp.buf.definition()
+command! -buffer        NuwikiTabDropLink lua require('nuwiki.commands').follow_link_drop()
 command! -buffer        NuwikiRemoveDone             lua require('nuwiki.commands').list_remove_done()
 command! -buffer -range NuwikiRemoveCheckbox         lua require('nuwiki.commands').list_remove_checkbox()
 command! -buffer        NuwikiRemoveCheckboxInList   lua require('nuwiki.commands').list_remove_checkbox_in_list()

lua/nuwiki/commands.lua

@@ -73,6 +73,10 @@ local function open_uri(uri, tab)
     return
   end
   local path = vim.uri_to_fname(uri)
+  if tab == 'tabdrop' then
+    vim.cmd('tab drop ' .. vim.fn.fnameescape(path))
+    return
+  end
   local cmd
   if tab == 'split' then
     cmd = 'split'
@@ -206,6 +210,32 @@ function M.badd_link()
   end
 end
 
+--- `:VimwikiTabDropLink` — open the link target in a tab, reusing an
+--- existing tab/window if the file is already shown (`:tab drop`). Uses
+--- the LSP definition response to resolve the target file.
+function M.follow_link_drop()
+  local client = find_client()
+  if not client then
+    vim.notify('nuwiki: language server not attached', vim.log.levels.ERROR)
+    return
+  end
+  local params = position_params(client)
+  params.textDocument = { uri = buf_uri() }
+  local req = client.request
+  local handler = function(_, result)
+    local loc
+    if type(result) == 'table' then
+      loc = result[1] or result
+    end
+    local uri = type(loc) == 'table' and (loc.uri or loc.targetUri) or nil
+    open_uri(uri, 'tabdrop')
+  end
+  local bufnr = vim.api.nvim_get_current_buf()
+  if type(req) == 'function' then
+    client:request('textDocument/definition', params, handler, bufnr)
+  end
+end
+
 function M.follow_link_or_create()
   if cursor_inside_wikilink() then
     vim.lsp.buf.definition()

lua/nuwiki/keymaps.lua

@@ -164,8 +164,8 @@ function M.attach(bufnr, mappings)
         { desc = 'nuwiki: follow link in split' }, bufnr)
     map('n', '<C-CR>',  function() vim.cmd('vsplit'); cmd.follow_link_or_create() end,
         { desc = 'nuwiki: follow link in vsplit' }, bufnr)
-    map('n', '<C-S-CR>', function() vim.cmd('tabnew'); cmd.follow_link_or_create() end,
+    map('n', '<C-S-CR>', cmd.follow_link_drop,
-        { desc = 'nuwiki: follow link in new tab' }, bufnr)
+        { desc = 'nuwiki: follow link in tab (reuse existing)' }, bufnr)
     map('n', '<BS>',    '<C-o>', { desc = 'nuwiki: go back', remap = true }, bufnr)
     map('n', '<Tab>',   link.next, { desc = 'nuwiki: next wikilink' }, bufnr)
     map('n', '<S-Tab>', link.prev, { desc = 'nuwiki: prev wikilink' }, bufnr)