Resize window edge determination looks strange with winfixwidth and winfixheight

[KSR-Yasuda]

For example below,
the window * is considered not right edge,
and it works as if the window's right partition can be movable
(i.e left key (j) decreases window width / right key (l) increases).

This looks quite strange.

+-----+-----+-----+
|     |     |     |
|     |  *  | wfw |
|     |     |     |
+-----+-----+-----+
      ^
      This moves

---

I tried to fix it like below, however, it is still incomplete.

--- a/autoload/winresizer.vim
+++ b/autoload/winresizer.vim
@@ -13,12 +13,12 @@ fun! winresizer#getEdgeInfo()
   let chk_direct = ['left', 'down', 'up', 'right']
   let result = {}
   for direct in chk_direct
-    exe 'let result["' . direct . '"] = ' . !winresizer#canMoveCursorFromCurrentWindow(direct)
+    exe 'let result["' . direct . '"] = ' . !winresizer#canMoveCursorToResizableWindowFromCurrentWindow(direct)
   endfor
   return result
 endfun
 
-fun! winresizer#canMoveCursorFromCurrentWindow(direct)
+fun! winresizer#canMoveCursorToResizableWindowFromCurrentWindow(direct)
   let map_direct = {'left':'h', 'down':'j', 'up':'k', 'right':'l'}
   if has_key(map_direct, a:direct)
     let direct = map_direct[a:direct]
@@ -28,8 +28,9 @@ fun! winresizer#canMoveCursorFromCurrentWindow(direct)
   let from = winnr()
   exe "wincmd " . direct
   let to = winnr()
+  let fixed = (a:direct ==# 'up' || a:direct ==# 'down') ? &winfixheight : &winfixwidth
   exe from . "wincmd w"
-  return from != to
+  return from != to && !fixed
 endfun
 
 fun! winresizer#swapTo(direct)

With the window arrangement like below,
the right partition of the window * moves.

+-----+-----+-----+
|     |     |     |
|     |     | wfw |
|     |     |     |
|     |     +-----+
|     |     |     |
|     |  *  | wfw |
|     |     |     |
|     |     +-----+
|     |     |     |
|     |     | wfw |
|     |     |     |
+-----+-----+-----+
            ^
            This moves