Automatically set nowinfixwidth to fix #416

Author: lambdalisue

autoload/fern/internal/drawer/auto_winfixwidth.vim

@@ -5,6 +5,10 @@ function! fern#internal#drawer#auto_winfixwidth#init() abort
 
   augroup fern_internal_drawer_auto_winfixwidth_init
     autocmd! * <buffer>
-    autocmd BufEnter <buffer> setlocal winfixwidth
+    autocmd BufEnter <buffer> call s:set_winfixwidth()
   augroup END
 endfunction
+
+function! s:set_winfixwidth() abort
+  let &l:winfixwidth = winnr('$') isnot# 1
+endfunction

doc/fern.txt

@@ -401,7 +401,9 @@ VARIABLE						*fern-variable*
 
 *g:fern#disable_drawer_auto_winfixwidth*
 	Set 1 to disable automatically enable 'winfixwidth' to drawer on
-	|BufEnter| autocmd.
+	|BufEnter| autocmd. Note that it automatically set 'nowinfixwidth' on
+	the autocmd when there is only one window.
+
 	Default: 0
 
 *g:fern#disable_drawer_auto_resize*