1 files changed, 7 insertions, 7 deletions

diff --git a/src/window.c b/src/window.c
index 2fd4d286eba..766c291820f 100644
--- a/src/window.c
+++ b/src/window.c
@@ -2670,12 +2670,12 @@ window_fixed_size_p (w, width_p, check_siblings_p)
         {
           Lisp_Object child;
 
-          for (child = w->prev; !NILP (child); child = XWINDOW (child)->prev)
+          for (child = w->prev; WINDOWP (child); child = XWINDOW (child)->prev)
             if (!window_fixed_size_p (XWINDOW (child), width_p, 0))
               break;
 
           if (NILP (child))
-            for (child = w->next; !NILP (child); child = XWINDOW (child)->next)
+            for (child = w->next; WINDOWP (child); child = XWINDOW (child)->next)
               if (!window_fixed_size_p (XWINDOW (child), width_p, 0))
                 break;
 
@@ -4291,10 +4291,10 @@ enlarge_window (window, delta, horiz_flag)
 
   /* Find the total we can get from other siblings without deleting them.  */
   maximum = 0;
-  for (next = p->next; ! NILP (next); next = XWINDOW (next)->next)
+  for (next = p->next; WINDOWP (next); next = XWINDOW (next)->next)
     maximum += (*sizefun) (next) - window_min_size (XWINDOW (next),
                                                     horiz_flag, 0, 0);
-  for (prev = p->prev; ! NILP (prev); prev = XWINDOW (prev)->prev)
+  for (prev = p->prev; WINDOWP (prev); prev = XWINDOW (prev)->prev)
     maximum += (*sizefun) (prev) - window_min_size (XWINDOW (prev),
                                                     horiz_flag, 0, 0);
 
@@ -4442,10 +4442,10 @@ enlarge_window (window, delta, horiz_flag)
           Lisp_Object s;
           int n = 1;
 
-          for (s = w->next; !NILP (s); s = XWINDOW (s)->next)
+          for (s = w->next; WINDOWP (s); s = XWINDOW (s)->next)
             if (!window_fixed_size_p (XWINDOW (s), horiz_flag, 0))
               ++n;
-          for (s = w->prev; !NILP (s); s = XWINDOW (s)->prev)
+          for (s = w->prev; WINDOWP (s); s = XWINDOW (s)->prev)
             if (!window_fixed_size_p (XWINDOW (s), horiz_flag, 0))
               ++n;
 
@@ -4701,7 +4701,7 @@ shrink_window_lowest_first (w, height)
       /* Find the last child.  We are taking space from lowest windows
          first, so we iterate over children from the last child
          backwards.  */
-      for (child = w->vchild; !NILP (child); child = XWINDOW (child)->next)
+      for (child = w->vchild; WINDOWP (child); child = XWINDOW (child)->next)
         last_child = child;
 
       /* Assign new heights.  We leave only MIN_SAFE_WINDOW_HEIGHT.  */