(do_symval_forwarding): Handle display-local vars.

(store_symval_forwarding, find_symbol_value): Likewise.
(Fmake_variable_buffer_local): Disallow display-local vars here.
(Fmake_local_variable): Likewise.

1 files changed, 29 insertions, 13 deletions

diff --git a/src/data.c b/src/data.c
index 93e3811be4b..298c0b646db 100644
--- a/src/data.c
+++ b/src/data.c
@@ -642,6 +642,11 @@ do_symval_forwarding (valcontents)
       case Lisp_Misc_Buffer_Objfwd:
         offset = XBUFFER_OBJFWD (valcontents)->offset;
         return *(Lisp_Object *)(offset + (char *)current_buffer);
+
+      case Lisp_Misc_Display_Objfwd:
+        offset = XDISPLAY_OBJFWD (valcontents)->offset;
+        return *(Lisp_Object *)(offset
+                                + (char *)get_perdisplay (selected_frame));
       }
   return valcontents;
 }
@@ -685,8 +690,15 @@ store_symval_forwarding (sym, valcontents, newval)
               buffer_slot_type_mismatch (offset);
 
             *(Lisp_Object *)(offset + (char *)current_buffer) = newval;
-            break;
           }
+          break;
+
+        case Lisp_Misc_Display_Objfwd:
+          (*(Lisp_Object *)((char *)get_perdisplay (selected_frame)
+                            + XDISPLAY_OBJFWD (valcontents)->offset))
+            = newval;
+          break;
+
         default:
           goto def;
         }
@@ -711,9 +723,9 @@ static Lisp_Object
 swap_in_symval_forwarding (sym, valcontents)
      Lisp_Object sym, valcontents;
 {
-  /* valcontents is a list
+  /* valcontents is a pointer to a struct resembling the cons
      (REALVALUE BUFFER CURRENT-ALIST-ELEMENT . DEFAULT-VALUE)).
-     
+
      CURRENT-ALIST-ELEMENT is a pointer to an element of BUFFER's
      local_var_alist, that being the element whose car is this
      variable.  Or it can be a pointer to the
@@ -784,6 +796,10 @@ find_symbol_value (sym)
         case Lisp_Misc_Buffer_Objfwd:
           return *(Lisp_Object *)(XBUFFER_OBJFWD (valcontents)->offset
                                   + (char *)current_buffer);
+
+        case Lisp_Misc_Display_Objfwd:
+          return *(Lisp_Object *)(XDISPLAY_OBJFWD (valcontents)->offset
+                                  + (char *)get_perdisplay (selected_frame));
         }
     }
 
@@ -1101,10 +1117,10 @@ The function `default-value' gets the default value and `set-default' sets it.")
 
   CHECK_SYMBOL (sym, 0);
 
-  if (EQ (sym, Qnil) || EQ (sym, Qt))
+  valcontents = XSYMBOL (sym)->value;
+  if (EQ (sym, Qnil) || EQ (sym, Qt) || DISPLAY_OBJFWDP (valcontents))
     error ("Symbol %s may not be buffer-local", XSYMBOL (sym)->name->data);
 
-  valcontents = XSYMBOL (sym)->value;
   if (BUFFER_LOCAL_VALUEP (valcontents) || BUFFER_OBJFWDP (valcontents))
     return sym;
   if (SOME_BUFFER_LOCAL_VALUEP (valcontents))
@@ -1144,14 +1160,14 @@ Use `make-local-hook' instead.")
 
   CHECK_SYMBOL (sym, 0);
 
-  if (EQ (sym, Qnil) || EQ (sym, Qt))
+  valcontents = XSYMBOL (sym)->value;
+  if (EQ (sym, Qnil) || EQ (sym, Qt) || DISPLAY_OBJFWDP (valcontents))
     error ("Symbol %s may not be buffer-local", XSYMBOL (sym)->name->data);
 
-  valcontents = XSYMBOL (sym)->value;
   if (BUFFER_LOCAL_VALUEP (valcontents) || BUFFER_OBJFWDP (valcontents))
     {
       tem = Fboundp (sym);
-      
+
       /* Make sure the symbol has a local value in this particular buffer,
          by setting it to the same value it already has.  */
       Fset (sym, (EQ (tem, Qt) ? Fsymbol_value (sym) : Qunbound));
@@ -1576,7 +1592,7 @@ NUM may be an integer or a floating point number.")
       char pigbuf[350]; /* see comments in float_to_string */
 
       float_to_string (pigbuf, XFLOAT(num)->data);
-      return build_string (pigbuf);      
+      return build_string (pigbuf);
     }
 #endif /* LISP_FLOAT_TYPE */
 
@@ -1609,7 +1625,7 @@ It ignores leading spaces and tabs.")
 
   return make_number (atoi (p));
 }
-  
+
 enum arithop
   { Aadd, Asub, Amult, Adiv, Alogand, Alogior, Alogxor, Amax, Amin };
 
@@ -1698,7 +1714,7 @@ float_arith_driver (accum, argnum, code, nargs, args)
 {
   register Lisp_Object val;
   double next;
-  
+
   for (; argnum < nargs; argnum++)
     {
       val = args[argnum];    /* using args[argnum] as argument to CHECK_NUMBER_... */
@@ -1864,7 +1880,7 @@ Both X and Y must be numbers or markers.")
 
   if (i2 == 0)
     Fsignal (Qarith_error, Qnil);
-  
+
   i1 %= i2;
 
   /* If the "remainder" comes out with the wrong sign, fix it.  */
@@ -2374,7 +2390,7 @@ init_data ()
     return;
 #endif /* CANNOT_DUMP */
   signal (SIGFPE, arith_error);
-  
+
 #ifdef uts
   signal (SIGEMT, arith_error);
 #endif /* uts */