* xfns.c (Fx_create_frame, Fx_display_list):

* window.c (window_fixed_size_p, enlarge_window, shrink_window_lowest_first):
* macterm.c (init_font_name_table):
* macfns.c (Fx_create_frame, Fx_display_list):
* lread.c (close_load_descs):
* keyboard.c (read_char_x_menu_prompt):
* fns.c (Fmember, Fmemql, Fdelete, Fset_char_table_parent):
* coding.c (code_convert_region_unwind): Test the type of an object
rather than just !NILP before extracting data from it.

1 files changed, 5 insertions, 4 deletions

diff --git a/src/fns.c b/src/fns.c
index f881ed53f88..7ec0056332a 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -1451,7 +1451,7 @@ The value is actually the tail of LIST whose car is ELT.  */)
      Lisp_Object list;
 {
   register Lisp_Object tail;
-  for (tail = list; !NILP (tail); tail = XCDR (tail))
+  for (tail = list; CONSP (tail); tail = XCDR (tail))
     {
       register Lisp_Object tem;
       CHECK_LIST_CONS (tail, list);
@@ -1502,7 +1502,7 @@ The value is actually the tail of LIST whose car is ELT.  */)
   if (!FLOATP (elt))
     return Fmemq (elt, list);
 
-  for (tail = list; !NILP (tail); tail = XCDR (tail))
+  for (tail = list; CONSP (tail); tail = XCDR (tail))
     {
       register Lisp_Object tem;
       CHECK_LIST_CONS (tail, list);
@@ -1806,7 +1806,7 @@ to be sure of changing the value of `foo'.  */)
     {
       Lisp_Object tail, prev;
 
-      for (tail = seq, prev = Qnil; !NILP (tail); tail = XCDR (tail))
+      for (tail = seq, prev = Qnil; CONSP (tail); tail = XCDR (tail))
         {
           CHECK_LIST_CONS (tail, seq);
 
@@ -2440,7 +2440,8 @@ Return PARENT.  PARENT must be either nil or another char-table.  */)
     {
       CHECK_CHAR_TABLE (parent);
 
-      for (temp = parent; !NILP (temp); temp = XCHAR_TABLE (temp)->parent)
+      for (temp = parent; CHAR_TABLE_P (temp);
+           temp = XCHAR_TABLE (temp)->parent)
         if (EQ (temp, char_table))
           error ("Attempt to make a chartable be its own parent");
     }