Inspect buffer options to determine need for eol. (#158)

The eol option will be set if the vim found an eol at the eof. This,
combined with the binary and fixeol options can be used to determine if
the file will have eol characters at the end-of-file after vim saves the
file.

Author: Adam Labbe

autoload/lsp.vim

@@ -590,10 +590,17 @@ function! lsp#get_whitelisted_servers(...) abort
     return l:active_servers
 endfunction
 
+function! s:requires_eol_at_eof(buf) abort
+    let l:file_ends_with_eol = getbufvar(a:buf, '&eol')
+    let l:vim_will_save_with_eol = !getbufvar(a:buf, '&binary') &&
+                \ getbufvar(a:buf, '&fixeol')
+    return l:file_ends_with_eol || l:vim_will_save_with_eol
+endfunction
+
 function! s:get_text_document_text(buf) abort
     let l:buf_fileformat = getbufvar(a:buf, '&fileformat')
-    let l:line_ending = {'unix': "\n", 'dos': "\r\n", 'mac': "\r"}[l:buf_fileformat]
-    return join(getbufline(a:buf, 1, '$'), l:line_ending)
+    let l:eol = {'unix': "\n", 'dos': "\r\n", 'mac': "\r"}[l:buf_fileformat]
+    return join(getbufline(a:buf, 1, '$'), l:eol).(s:requires_eol_at_eof(a:buf) ? l:eol : '')
 endfunction
 
 function! s:get_text_document(buf, buffer_info) abort