Permit zero value for 'child-frame-border-width' parameter (Bug#46184)

* doc/lispref/frames.texi (Layout Parameters): Update entry on
'child-frame-border-width' parameter.
* src/frame.c (make_frame): Init child_frame_border_width to -1.
(Fframe_child_frame_border_width): Return internal border width if
child frame border width parameter is nil.
(gui_report_frame_params): Report nil as child frame border
width parameter if the frame value is negative.
* src/frame.h (FRAME_INTERNAL_BORDER_WIDTH): Return value of
child frame border width only if it is not negative.
* src/xfns.c (Fx_create_frame): Default child frame border to -1
when recording it in its frame slot via gui_default_parameter.
* src/nsfns.m (ns_set_child_frame_border_width): Handle nil ARG.
(Fx_create_frame): Default child frame border width parameter to
nil.
* src/w32fns.c (w32_set_child_frame_border_width): Handle nil ARG.
(Fx_create_frame): Default child frame border width parameter to
nil.
* src/xfns.c (x_set_child_frame_border_width): Handle nil ARG.
(Fx_create_frame): Default child frame border width parameter to
nil.

1 files changed, 19 insertions, 17 deletions

diff --git a/src/xfns.c b/src/xfns.c
index cac41ee4856..481ee0e2255 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -1803,7 +1803,14 @@ x_change_tool_bar_height (struct frame *f, int height)
 static void
 x_set_child_frame_border_width (struct frame *f, Lisp_Object arg, Lisp_Object oldval)
 {
-  int border = check_int_nonnegative (arg);
+  int border;
+
+  if (NILP (arg))
+    border = -1;
+  else if (RANGED_FIXNUMP (0, arg, INT_MAX))
+    border = XFIXNAT (arg);
+  else
+    signal_error ("Invalid child frame border width", arg);
 
   if (border != FRAME_CHILD_FRAME_BORDER_WIDTH (f))
     {
@@ -3920,36 +3927,31 @@ This function is an internal primitive--use `make-frame' instead.  */)
 		       parms);
     }
 
+  gui_default_parameter (f, parms, Qinternal_border_width,
+#ifdef USE_GTK /* We used to impose 0 in xg_create_frame_widgets.  */
+                         make_fixnum (0),
+#else
+                         make_fixnum (1),
+#endif
+                         "internalBorderWidth", "internalBorderWidth",
+                         RES_TYPE_NUMBER);
+
   /* Same for child frames.  */
   if (NILP (Fassq (Qchild_frame_border_width, parms)))
     {
       Lisp_Object value;
 
       value = gui_display_get_arg (dpyinfo, parms, Qchild_frame_border_width,
-                                   "childFrameBorderWidth", "childFrameBorderWidth",
+                                   "childFrameBorder", "childFrameBorder",
                                    RES_TYPE_NUMBER);
       if (! EQ (value, Qunbound))
 	parms = Fcons (Fcons (Qchild_frame_border_width, value),
 		       parms);
-
     }
 
-  gui_default_parameter (f, parms, Qchild_frame_border_width,
-#ifdef USE_GTK /* We used to impose 0 in xg_create_frame_widgets.  */
-			 make_fixnum (0),
-#else
-			 make_fixnum (1),
-#endif
+  gui_default_parameter (f, parms, Qchild_frame_border_width, Qnil,
 			 "childFrameBorderWidth", "childFrameBorderWidth",
 			 RES_TYPE_NUMBER);
-  gui_default_parameter (f, parms, Qinternal_border_width,
-#ifdef USE_GTK /* We used to impose 0 in xg_create_frame_widgets.  */
-                         make_fixnum (0),
-#else
-                         make_fixnum (1),
-#endif
-                         "internalBorderWidth", "internalBorderWidth",
-                         RES_TYPE_NUMBER);
   gui_default_parameter (f, parms, Qright_divider_width, make_fixnum (0),
                          NULL, NULL, RES_TYPE_NUMBER);
   gui_default_parameter (f, parms, Qbottom_divider_width, make_fixnum (0),