Merge remote-tracking branch 'savannah/master' into native-comp

17 files changed, 273 insertions, 51 deletions

diff --git a/src/cmds.c b/src/cmds.c
index 1547db80e88..c8a96d918cd 100644
--- a/src/cmds.c
+++ b/src/cmds.c
@@ -99,6 +99,7 @@ DEFUN ("forward-line", Fforward_line, Sforward_line, 0, 1, "^p",
 Precisely, if point is on line I, move to the start of line I + N
 \("start of line" in the logical order).
 If there isn't room, go as far as possible (no error).
+Interactively, N is the numeric prefix argument and defaults to 1.
 
 Returns the count of lines left to move.  If moving forward,
 that is N minus number of lines moved; if backward, N plus number
diff --git a/src/dispextern.h b/src/dispextern.h
index 3ad98b8344e..f4e872644db 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -1826,6 +1826,7 @@ enum face_id
   WINDOW_DIVIDER_FIRST_PIXEL_FACE_ID,
   WINDOW_DIVIDER_LAST_PIXEL_FACE_ID,
   INTERNAL_BORDER_FACE_ID,
+  CHILD_FRAME_BORDER_FACE_ID,
   TAB_BAR_FACE_ID,
   TAB_LINE_FACE_ID,
   BASIC_FACE_ID_SENTINEL
diff --git a/src/editfns.c b/src/editfns.c
index 6f04c998915..e3285494c14 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -52,6 +52,9 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "window.h"
 #include "blockinput.h"
 
+#ifdef WINDOWSNT
+# include "w32common.h"
+#endif
 static void update_buffer_properties (ptrdiff_t, ptrdiff_t);
 static Lisp_Object styled_format (ptrdiff_t, Lisp_Object *, bool);
 
@@ -121,12 +124,14 @@ init_editfns (void)
   else if (NILP (Vuser_full_name))
     Vuser_full_name = build_string ("unknown");
 
-#ifdef HAVE_SYS_UTSNAME_H
+#if defined HAVE_SYS_UTSNAME_H
   {
     struct utsname uts;
     uname (&uts);
     Voperating_system_release = build_string (uts.release);
   }
+#elif defined WINDOWSNT
+  Voperating_system_release = build_string (w32_version_string ());
 #else
   Voperating_system_release = Qnil;
 #endif
@@ -4479,7 +4484,9 @@ functions if all the text being accessed has this property.  */);
                doc: /* The user's name, based upon the real uid only.  */);
 
   DEFVAR_LISP ("operating-system-release", Voperating_system_release,
-               doc: /* The release of the operating system Emacs is running on.  */);
+               doc: /* The kernel version of the operating system on which Emacs is running.
+The value is a string.  It can also be nil if Emacs doesn't
+know how to get the kernel version on the underlying OS.  */);
 
   DEFVAR_BOOL ("binary-as-unsigned",
                binary_as_unsigned,
diff --git a/src/emacs.c b/src/emacs.c
index c6581bba37e..acf8a17a12a 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -186,7 +186,8 @@ bool build_details;
 /* Name for the server started by the daemon.*/
 static char *daemon_name;
 
-/* 0 not a daemon, 1 new-style (foreground), 2 old-style (background).  */
+/* 0 not a daemon, 1 new-style (foreground), 2 old-style (background).
+   A negative value means the daemon initialization was already done.  */
 int daemon_type;
 
 #ifndef WINDOWSNT
@@ -2387,7 +2388,10 @@ all of which are called before Emacs is actually killed.  */
   int exit_code;
 
 #ifdef HAVE_LIBSYSTEMD
-  sd_notify(0, "STOPPING=1");
+  /* Notify systemd we are shutting down, but only if we have notified
+     it about startup.  */
+  if (daemon_type == -1)
+    sd_notify(0, "STOPPING=1");
 #endif /* HAVE_LIBSYSTEMD */
 
   /* Fsignal calls emacs_abort () if it sees that waiting_for_input is
@@ -2903,7 +2907,7 @@ from the parent process and its tty file descriptors.  */)
     }
 
   /* Set it to an invalid value so we know we've already run this function.  */
-  daemon_type = -1;
+  daemon_type = -daemon_type;
 
 #else  /* WINDOWSNT */
   /* Signal the waiting emacsclient process.  */
diff --git a/src/fns.c b/src/fns.c
index 7ab2e8f1a03..bd4afa0c4e9 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -4599,33 +4599,29 @@ sweep_weak_table (struct Lisp_Hash_Table *h, bool remove_entries_p)
 EMACS_UINT
 hash_string (char const *ptr, ptrdiff_t len)
 {
-  EMACS_UINT const *p   = (EMACS_UINT const *) ptr;
-  EMACS_UINT const *end = (EMACS_UINT const *) (ptr + len);
+  char const *p   = ptr;
+  char const *end = ptr + len;
   EMACS_UINT hash = len;
   /* At most 8 steps.  We could reuse SXHASH_MAX_LEN, of course,
    * but dividing by 8 is cheaper.  */
-  ptrdiff_t step = 1 + ((end - p) >> 3);
+  ptrdiff_t step = sizeof hash + ((end - p) >> 3);
 
-  /* Beware: `end` might be unaligned, so `p < end` is not always the same
-   * as `p <= end - 1`.  */
-  while (p <= end - 1)
+  while (p + sizeof hash <= end)
     {
-      EMACS_UINT c = *p;
+      EMACS_UINT c;
+      /* We presume that the compiler will replace this `memcpy` with
+         a single load/move instruction when applicable.  */
+      memcpy (&c, p, sizeof hash);
       p += step;
       hash = sxhash_combine (hash, c);
     }
-  if (p < end)
-    { /* A few last bytes remain (smaller than an EMACS_UINT).  */
-      /* FIXME: We could do this without a loop, but it'd require
-         endian-dependent code :-(  */
-      char const *p1 = (char const *)p;
-      char const *end1 = (char const *)end;
-      do
-        {
-          unsigned char c = *p1++;
-          hash = sxhash_combine (hash, c);
-        }
-      while (p1 < end1);
+  /* A few last bytes may remain (smaller than an EMACS_UINT).  */
+  /* FIXME: We could do this without a loop, but it'd require
+     endian-dependent code :-(  */
+  while (p < end)
+    {
+      unsigned char c = *p++;
+      hash = sxhash_combine (hash, c);
     }
 
   return hash;
diff --git a/src/frame.c b/src/frame.c
index 599c4075f88..a2167ce1e49 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -3543,6 +3543,13 @@ DEFUN ("frame-fringe-width", Ffringe_width, Sfringe_width, 0, 1, 0,
   return make_fixnum (FRAME_TOTAL_FRINGE_WIDTH (decode_any_frame (frame)));
 }
 
+DEFUN ("frame-child-frame-border-width", Fframe_child_frame_border_width, Sframe_child_frame_border_width, 0, 1, 0,
+       doc: /* Return width of FRAME's child-frame border in pixels.  */)
+  (Lisp_Object frame)
+{
+  return make_fixnum (FRAME_CHILD_FRAME_BORDER_WIDTH (decode_any_frame (frame)));
+}
+
 DEFUN ("frame-internal-border-width", Fframe_internal_border_width, Sframe_internal_border_width, 0, 1, 0,
        doc: /* Return width of FRAME's internal border in pixels.  */)
   (Lisp_Object frame)
@@ -3759,6 +3766,7 @@ static const struct frame_parm_table frame_parms[] =
   {"foreground-color",          -1},
   {"icon-name",                 SYMBOL_INDEX (Qicon_name)},
   {"icon-type",                 SYMBOL_INDEX (Qicon_type)},
+  {"child-frame-border-width",  SYMBOL_INDEX (Qchild_frame_border_width)},
   {"internal-border-width",     SYMBOL_INDEX (Qinternal_border_width)},
   {"right-divider-width",       SYMBOL_INDEX (Qright_divider_width)},
   {"bottom-divider-width",      SYMBOL_INDEX (Qbottom_divider_width)},
@@ -4302,6 +4310,8 @@ gui_report_frame_params (struct frame *f, Lisp_Object *alistptr)
 
   store_in_alist (alistptr, Qborder_width,
                   make_fixnum (f->border_width));
+  store_in_alist (alistptr, Qchild_frame_border_width,
+                  make_fixnum (FRAME_CHILD_FRAME_BORDER_WIDTH (f)));
   store_in_alist (alistptr, Qinternal_border_width,
                   make_fixnum (FRAME_INTERNAL_BORDER_WIDTH (f)));
   store_in_alist (alistptr, Qright_divider_width,
@@ -5999,6 +6009,7 @@ syms_of_frame (void)
   DEFSYM (Qhorizontal_scroll_bars, "horizontal-scroll-bars");
   DEFSYM (Qicon_name, "icon-name");
   DEFSYM (Qicon_type, "icon-type");
+  DEFSYM (Qchild_frame_border_width, "child-frame-border-width");
   DEFSYM (Qinternal_border_width, "internal-border-width");
   DEFSYM (Qleft_fringe, "left-fringe");
   DEFSYM (Qline_spacing, "line-spacing");
@@ -6423,6 +6434,7 @@ iconify the top level frame instead.  */);
   defsubr (&Sscroll_bar_width);
   defsubr (&Sscroll_bar_height);
   defsubr (&Sfringe_width);
+  defsubr (&Sframe_child_frame_border_width);
   defsubr (&Sframe_internal_border_width);
   defsubr (&Sright_divider_width);
   defsubr (&Sbottom_divider_width);
diff --git a/src/frame.h b/src/frame.h
index 8cf41dc0046..9b0852c7b9c 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -534,6 +534,10 @@ struct frame
   /* Border width of the frame window as known by the (X) window system.  */
   int border_width;
 
+  /* Width of child frames' internal border.  Acts as
+     internal_border_width for child frames.  */
+  int child_frame_border_width;
+
   /* Width of the internal border.  This is a line of background color
      just inside the window's border.  When the frame is selected,
      a highlighting is displayed inside the internal border.  */
@@ -1432,11 +1436,27 @@ FRAME_TOTAL_FRINGE_WIDTH (struct frame *f)
   return FRAME_LEFT_FRINGE_WIDTH (f) + FRAME_RIGHT_FRINGE_WIDTH (f);
 }
 
-/* Pixel-width of internal border lines.  */
+INLINE int
+FRAME_CHILD_FRAME_BORDER_WIDTH (struct frame *f)
+{
+  return frame_dimension (f->child_frame_border_width);
+}
+
+/* Pixel-width of internal border.  Uses child_frame_border_width for
+   child frames if possible, and falls back on internal_border_width
+   otherwise.  */
 INLINE int
 FRAME_INTERNAL_BORDER_WIDTH (struct frame *f)
 {
+#ifdef HAVE_WINDOW_SYSTEM
+  return FRAME_PARENT_FRAME(f)
+    ? (f->child_frame_border_width
+       ? FRAME_CHILD_FRAME_BORDER_WIDTH(f)
+       : frame_dimension (f->internal_border_width))
+    : frame_dimension (f->internal_border_width);
+#else
   return frame_dimension (f->internal_border_width);
+#endif
 }
 
 /* Pixel-size of window divider lines.  */
diff --git a/src/nsfns.m b/src/nsfns.m
index 24ea7d7f63b..c383e2f7ecf 100644
--- a/src/nsfns.m
+++ b/src/nsfns.m
@@ -687,6 +687,21 @@ ns_set_tool_bar_lines (struct frame *f, Lisp_Object value, Lisp_Object oldval)
   }
 }
 
+static void
+ns_set_child_frame_border_width (struct frame *f, Lisp_Object arg, Lisp_Object oldval)
+{
+  int old_width = FRAME_CHILD_FRAME_BORDER_WIDTH (f);
+  int new_width = check_int_nonnegative (arg);
+
+  if (new_width == old_width)
+    return;
+  f->child_frame_border_width = new_width;
+
+  if (FRAME_NATIVE_WINDOW (f) != 0)
+    adjust_frame_size (f, -1, -1, 3, 0, Qchild_frame_border_width);
+
+  SET_FRAME_GARBAGED (f);
+}
 
 static void
 ns_set_internal_border_width (struct frame *f, Lisp_Object arg, Lisp_Object oldval)
@@ -912,6 +927,7 @@ frame_parm_handler ns_frame_parm_handlers[] =
   ns_set_foreground_color,
   ns_set_icon_name,
   ns_set_icon_type,
+  ns_set_child_frame_border_width,
   ns_set_internal_border_width,
   gui_set_right_divider_width, /* generic OK */
   gui_set_bottom_divider_width, /* generic OK */
@@ -1197,6 +1213,9 @@ DEFUN ("x-create-frame", Fx_create_frame, Sx_create_frame,
   gui_default_parameter (f, parms, Qinternal_border_width, make_fixnum (2),
                          "internalBorderWidth", "InternalBorderWidth",
                          RES_TYPE_NUMBER);
+  gui_default_parameter (f, parms, Qchild_frame_border_width, make_fixnum (2),
+                         "childFrameBorderWidth", "childFrameBorderWidth",
+                         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),
diff --git a/src/nsterm.m b/src/nsterm.m
index df3934c5c34..1b2328628ee 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -3037,9 +3037,13 @@ ns_clear_under_internal_border (struct frame *f)
       NSRectEdge edge[] = {NSMinXEdge, NSMinYEdge, NSMaxXEdge, NSMaxYEdge};
 
       int face_id =
-        !NILP (Vface_remapping_alist)
-        ? lookup_basic_face (NULL, f, INTERNAL_BORDER_FACE_ID)
-        : INTERNAL_BORDER_FACE_ID;
+        (FRAME_PARENT_FRAME (f)
+         ? (!NILP (Vface_remapping_alist)
+            ? lookup_basic_face (NULL, f, CHILD_FRAME_BORDER_FACE_ID)
+            : CHILD_FRAME_BORDER_FACE_ID)
+         : (!NILP (Vface_remapping_alist)
+            ? lookup_basic_face (NULL, f, INTERNAL_BORDER_FACE_ID)
+            : INTERNAL_BORDER_FACE_ID));
       struct face *face = FACE_FROM_ID_OR_NULL (f, face_id);
 
       if (!face)
diff --git a/src/process.c b/src/process.c
index 1df4ed9ce03..3beb9cf7146 100644
--- a/src/process.c
+++ b/src/process.c
@@ -7217,7 +7217,7 @@ child_signal_read (int fd, void *data)
   eassert (0 <= fd);
   eassert (fd == child_signal_read_fd);
   char dummy;
-  if (emacs_read (fd, &dummy, 1) < 0)
+  if (emacs_read (fd, &dummy, 1) < 0 && errno != EAGAIN)
     emacs_perror ("reading from child signal FD");
 }
 #endif  /* !WINDOWSNT */
diff --git a/src/w32common.h b/src/w32common.h
index 90e88876aba..cbe05c5d8d1 100644
--- a/src/w32common.h
+++ b/src/w32common.h
@@ -50,6 +50,11 @@ extern int os_subtype;
 /* Cache system info, e.g., the NT page size.  */
 extern void cache_system_info (void);
 
+#ifdef WINDOWSNT
+/* Return a static buffer with the MS-Windows version string.  */
+extern char * w32_version_string (void);
+#endif
+
 typedef void (* VOIDFNPTR) (void);
 
 /* Load a function address from a DLL.  Cast the result via VOIDFNPTR
diff --git a/src/w32fns.c b/src/w32fns.c
index c1e18ff7fad..e93a0b85d93 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -1519,9 +1519,13 @@ w32_clear_under_internal_border (struct frame *f)
       int width = FRAME_PIXEL_WIDTH (f);
       int height = FRAME_PIXEL_HEIGHT (f);
       int face_id =
-        !NILP (Vface_remapping_alist)
-        ? lookup_basic_face (NULL, f, INTERNAL_BORDER_FACE_ID)
-        : INTERNAL_BORDER_FACE_ID;
+        (FRAME_PARENT_FRAME (f)
+         ? (!NILP (Vface_remapping_alist)
+            ? lookup_basic_face (NULL, f, CHILD_FRAME_BORDER_FACE_ID)
+            : CHILD_FRAME_BORDER_FACE_ID)
+         : (!NILP (Vface_remapping_alist)
+            ? lookup_basic_face (NULL, f, INTERNAL_BORDER_FACE_ID)
+            : INTERNAL_BORDER_FACE_ID));
       struct face *face = FACE_FROM_ID_OR_NULL (f, face_id);
 
       block_input ();
@@ -1548,6 +1552,32 @@ w32_clear_under_internal_border (struct frame *f)
     }
 }
 
+/**
+ * w32_set_child_frame_border_width:
+ *
+ * Set width of child frame F's internal border to ARG pixels.
+ * ARG < 0 is treated like ARG = 0.
+ */
+static void
+w32_set_child_frame_border_width (struct frame *f, Lisp_Object arg, Lisp_Object oldval)
+{
+  int argval = check_integer_range (arg, INT_MIN, INT_MAX);
+  int border = max (argval, 0);
+
+  if (border != FRAME_CHILD_FRAME_BORDER_WIDTH (f))
+    {
+      f->child_frame_border_width = border;
+
+      if (FRAME_NATIVE_WINDOW (f) != 0)
+        {
+          adjust_frame_size (f, -1, -1, 3, false, Qchild_frame_border_width);
+
+          if (FRAME_VISIBLE_P (f))
+            w32_clear_under_internal_border (f);
+        }
+    }
+}
+
 
 /**
  * w32_set_internal_border_width:
@@ -5873,6 +5903,28 @@ DEFUN ("x-create-frame", Fx_create_frame, Sx_create_frame,
                             parameters);
     }
 
+  /* Same for child frames.  */
+  if (NILP (Fassq (Qchild_frame_border_width, parameters)))
+    {
+      Lisp_Object value;
+
+      value = gui_display_get_arg (dpyinfo, parameters, Qchild_frame_border_width,
+                                   "childFrameBorderWidth", "childFrameBorderWidth",
+                                   RES_TYPE_NUMBER);
+      if (! EQ (value, Qunbound))
+        parameters = Fcons (Fcons (Qchild_frame_border_width, value),
+                       parameters);
+
+    }
+
+  gui_default_parameter (f, parameters, 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
+                         "childFrameBorderWidth", "childFrameBorderWidth",
+                         RES_TYPE_NUMBER);
   gui_default_parameter (f, parameters, Qinternal_border_width, make_fixnum (0),
                          "internalBorderWidth", "InternalBorder", RES_TYPE_NUMBER);
   gui_default_parameter (f, parameters, Qright_divider_width, make_fixnum (0),
@@ -9428,6 +9480,18 @@ cache_system_info (void)
   w32_num_mouse_buttons = GetSystemMetrics (SM_CMOUSEBUTTONS);
 }
 
+#ifdef WINDOWSNT
+char *
+w32_version_string (void)
+{
+  /* NNN.NNN.NNNNNNNNNN */
+  static char version_string[3 + 1 + 3 + 1 + 10 + 1];
+  _snprintf (version_string, sizeof version_string, "%d.%d.%d",
+             w32_major_version, w32_minor_version, w32_build_number);
+  return version_string;
+}
+#endif
+
 #ifdef EMACSDEBUG
 void
 _DebPrint (const char *fmt, ...)
@@ -10232,6 +10296,7 @@ frame_parm_handler w32_frame_parm_handlers[] =
   w32_set_foreground_color,
   w32_set_icon_name,
   w32_set_icon_type,
+  w32_set_child_frame_border_width,
   w32_set_internal_border_width,
   gui_set_right_divider_width,
   gui_set_bottom_divider_width,
diff --git a/src/w32term.c b/src/w32term.c
index 109aa58d732..0ee805a8526 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -2404,14 +2404,29 @@ w32_draw_stretch_glyph_string (struct glyph_string *s)
   else if (!s->background_filled_p)
     {
       int background_width = s->background_width;
-      int x = s->x, left_x = window_box_left_offset (s->w, TEXT_AREA);
+      int x = s->x, text_left_x = window_box_left_offset (s->w, TEXT_AREA);
 
-      /* Don't draw into left margin, fringe or scrollbar area
-         except for header line and mode line.  */
-      if (x < left_x && !s->row->mode_line_p)
+      /* Don't draw into left fringe or scrollbar area except for
+         header line and mode line.  */
+      if (x < text_left_x && !s->row->mode_line_p)
         {
-          background_width -= left_x - x;
-          x = left_x;
+          int left_x = WINDOW_LEFT_SCROLL_BAR_AREA_WIDTH (s->w);
+          int right_x = text_left_x;
+
+          if (WINDOW_HAS_FRINGES_OUTSIDE_MARGINS (s->w))
+            left_x += WINDOW_LEFT_FRINGE_WIDTH (s->w);
+          else
+            right_x -= WINDOW_LEFT_FRINGE_WIDTH (s->w);
+
+          /* Adjust X and BACKGROUND_WIDTH to fit inside the space
+             between LEFT_X and RIGHT_X.  */
+          if (x < left_x)
+            {
+              background_width -= left_x - x;
+              x = left_x;
+            }
+          if (x + background_width > right_x)
+            background_width = right_x - x;
         }
       if (background_width > 0)
         w32_draw_glyph_string_bg_rect (s, x, s->y, background_width, s->height);
diff --git a/src/xdisp.c b/src/xdisp.c
index e1e4ff41365..11b9e1becfd 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -29813,7 +29813,8 @@ produce_stretch_glyph (struct it *it)
 #endif  /* HAVE_WINDOW_SYSTEM */
     height = 1;
 
-  if (width > 0 && it->line_wrap != TRUNCATE
+  if (width > 0
+      && it->area == TEXT_AREA && it->line_wrap != TRUNCATE
       && it->current_x + width > it->last_visible_x)
     {
       width = it->last_visible_x - it->current_x;
diff --git a/src/xfaces.c b/src/xfaces.c
index 258b365eda3..12087138e51 100644
--- a/src/xfaces.c
+++ b/src/xfaces.c
@@ -4914,6 +4914,7 @@ lookup_basic_face (struct window *w, struct frame *f, int face_id)
     case WINDOW_DIVIDER_FIRST_PIXEL_FACE_ID:    name = Qwindow_divider_first_pixel;     break;
     case WINDOW_DIVIDER_LAST_PIXEL_FACE_ID:     name = Qwindow_divider_last_pixel;      break;
     case INTERNAL_BORDER_FACE_ID:       name = Qinternal_border;        break;
+    case CHILD_FRAME_BORDER_FACE_ID:    name = Qchild_frame_border;     break;
 
     default:
       emacs_abort (); /* the caller is supposed to pass us a basic face id */
@@ -5620,6 +5621,7 @@ realize_basic_faces (struct frame *f)
       realize_named_face (f, Qwindow_divider_last_pixel,
                           WINDOW_DIVIDER_LAST_PIXEL_FACE_ID);
       realize_named_face (f, Qinternal_border, INTERNAL_BORDER_FACE_ID);
+      realize_named_face (f, Qchild_frame_border, CHILD_FRAME_BORDER_FACE_ID);
       realize_named_face (f, Qtab_bar, TAB_BAR_FACE_ID);
       realize_named_face (f, Qtab_line, TAB_LINE_FACE_ID);
 
@@ -6973,6 +6975,7 @@ syms_of_xfaces (void)
   DEFSYM (Qwindow_divider_first_pixel, "window-divider-first-pixel");
   DEFSYM (Qwindow_divider_last_pixel, "window-divider-last-pixel");
   DEFSYM (Qinternal_border, "internal-border");
+  DEFSYM (Qchild_frame_border, "child-frame-border");
 
   /* TTY color-related functions (defined in tty-colors.el).  */
   DEFSYM (Qtty_color_desc, "tty-color-desc");
diff --git a/src/xfns.c b/src/xfns.c
index 9ab537ca8d9..cac41ee4856 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -1800,6 +1800,28 @@ x_change_tool_bar_height (struct frame *f, int height)
 #endif /* USE_GTK */
 }
 
+static void
+x_set_child_frame_border_width (struct frame *f, Lisp_Object arg, Lisp_Object oldval)
+{
+  int border = check_int_nonnegative (arg);
+
+  if (border != FRAME_CHILD_FRAME_BORDER_WIDTH (f))
+    {
+      f->child_frame_border_width = border;
+
+#ifdef USE_X_TOOLKIT
+      if (FRAME_X_OUTPUT (f)->edit_widget)
+        widget_store_internal_border (FRAME_X_OUTPUT (f)->edit_widget);
+#endif
+
+      if (FRAME_X_WINDOW (f))
+        {
+          adjust_frame_size (f, -1, -1, 3, false, Qchild_frame_border_width);
+          x_clear_under_internal_border (f);
+        }
+    }
+
+}
 
 static void
 x_set_internal_border_width (struct frame *f, Lisp_Object arg, Lisp_Object oldval)
@@ -3897,6 +3919,29 @@ This function is an internal primitive--use `make-frame' instead.  */)
         parms = Fcons (Fcons (Qinternal_border_width, value),
                        parms);
     }
+
+  /* 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",
+                                   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
+                         "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),
@@ -7762,6 +7807,7 @@ frame_parm_handler x_frame_parm_handlers[] =
   x_set_foreground_color,
   x_set_icon_name,
   x_set_icon_type,
+  x_set_child_frame_border_width,
   x_set_internal_border_width,
   gui_set_right_divider_width,
   gui_set_bottom_divider_width,
diff --git a/src/xterm.c b/src/xterm.c
index b8374fed8b1..744b80c68a0 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -1293,9 +1293,13 @@ x_clear_under_internal_border (struct frame *f)
       int height = FRAME_PIXEL_HEIGHT (f);
       int margin = FRAME_TOP_MARGIN_HEIGHT (f);
       int face_id =
-        !NILP (Vface_remapping_alist)
-        ? lookup_basic_face (NULL, f, INTERNAL_BORDER_FACE_ID)
-        : INTERNAL_BORDER_FACE_ID;
+        (FRAME_PARENT_FRAME (f)
+         ? (!NILP (Vface_remapping_alist)
+            ? lookup_basic_face (NULL, f, CHILD_FRAME_BORDER_FACE_ID)
+            : CHILD_FRAME_BORDER_FACE_ID)
+         : (!NILP (Vface_remapping_alist)
+            ? lookup_basic_face (NULL, f, INTERNAL_BORDER_FACE_ID)
+            : INTERNAL_BORDER_FACE_ID));
       struct face *face = FACE_FROM_ID_OR_NULL (f, face_id);
 
       block_input ();
@@ -1360,9 +1364,13 @@ x_after_update_window_line (struct window *w, struct glyph_row *desired_row)
       {
         int y = WINDOW_TO_FRAME_PIXEL_Y (w, max (0, desired_row->y));
         int face_id =
-          !NILP (Vface_remapping_alist)
-          ? lookup_basic_face (NULL, f, INTERNAL_BORDER_FACE_ID)
-          : INTERNAL_BORDER_FACE_ID;
+          (FRAME_PARENT_FRAME (f)
+           ? (!NILP (Vface_remapping_alist)
+              ? lookup_basic_face (NULL, f, CHILD_FRAME_BORDER_FACE_ID)
+              : CHILD_FRAME_BORDER_FACE_ID)
+           : (!NILP (Vface_remapping_alist)
+              ? lookup_basic_face (NULL, f, INTERNAL_BORDER_FACE_ID)
+              : INTERNAL_BORDER_FACE_ID));
         struct face *face = FACE_FROM_ID_OR_NULL (f, face_id);
 
         block_input ();
@@ -3577,14 +3585,29 @@ x_draw_stretch_glyph_string (struct glyph_string *s)
   else if (!s->background_filled_p)
     {
       int background_width = s->background_width;
-      int x = s->x, left_x = window_box_left_offset (s->w, TEXT_AREA);
+      int x = s->x, text_left_x = window_box_left_offset (s->w, TEXT_AREA);
 
-      /* Don't draw into left margin, fringe or scrollbar area
-         except for header line and mode line.  */
-      if (x < left_x && !s->row->mode_line_p)
+      /* Don't draw into left fringe or scrollbar area except for
+         header line and mode line.  */
+      if (x < text_left_x && !s->row->mode_line_p)
         {
-          background_width -= left_x - x;
-          x = left_x;
+          int left_x = WINDOW_LEFT_SCROLL_BAR_AREA_WIDTH (s->w);
+          int right_x = text_left_x;
+
+          if (WINDOW_HAS_FRINGES_OUTSIDE_MARGINS (s->w))
+            left_x += WINDOW_LEFT_FRINGE_WIDTH (s->w);
+          else
+            right_x -= WINDOW_LEFT_FRINGE_WIDTH (s->w);
+
+          /* Adjust X and BACKGROUND_WIDTH to fit inside the space
+             between LEFT_X and RIGHT_X.  */
+          if (x < left_x)
+            {
+              background_width -= left_x - x;
+              x = left_x;
+            }
+          if (x + background_width > right_x)
+            background_width = right_x - x;
         }
       if (background_width > 0)
         x_draw_glyph_string_bg_rect (s, x, s->y, background_width, s->height);