Fix some tooltip related problems

Replace 'tooltip' frame parameter with a 'tooltip' member in
the frame structure.  For GTK+ builds use 'tip_last_frame' to
find the frame for which the currently visible tooltip was
made.  For modeline help-echoing have tooltips show applicable
actions only.

* lisp/bindings.el (mode-line-default-help-echo): New function
as default value of homonymous option.
* src/dispextern.h (tip_frame, tip_window): Remove
declarations.
* src/frame.c (make_frame): Initialize new frame structure
member 'tooltip'.
(Fframe_list, other_frames): Rewrite with new macro
FRAME_TOOLTIP_P.
* src/frame.h (struct frame): New member 'tooltip'.
(FRAME_TOOLTIP_P): New macro.
* src/gtkutil.c (xg_prepare_tooltip, xg_hide_tooltip): Rewrite
using boolean return values.
* src/nsfns.m (tip_frame): Remove declaration.
* src/w32fns.c (w32_display_monitor_attributes_list)
(w32_display_monitor_attributes_list_fallback): Rewrite with
new macro FRAME_TOOLTIP_P.
(tip_last_string, tip_last_frame, tip_last_parms): New Lisp
scalars replacing Lisp vector last_show_tip_args.
(x_create_tip_frame): Set new frame's 'tooltip' structure
member to true.
(x_hide_tip): Additionally test tip_frame for liveness.
(Fx_show_tip): Handle last_show_tip_args to tip_last_frame,
tip_last_string and tip_last_parms conversion.
(syms_of_w32fns): staticpro tip_last_frame, tip_last_string
and tip_last_parms instead of last_show_tip_args.
* src/w32term.c (w32_read_socket, x_new_font): Rewrite with
new macro FRAME_TOOLTIP_P.
* src/w32term.h (tip_window): Add external declaration.
* src/xdisp.c (x_consider_frame_title, prepare_menu_bars)
(should_produce_line_number): Rewrite with new macro
FRAME_TOOLTIP_P.
(note_mode_line_or_margin_highlight): If
`mode-line-default-help-echo' specifies a function, call it to
produce help echo string.
* src/xfns.c (x_make_monitor_attribute_list)
(Fx_display_monitor_attributes_list): Rewrite with
new macro FRAME_TOOLTIP_P.
(tip_last_string, tip_last_frame, tip_last_parms): New Lisp
scalars replacing Lisp vector last_show_tip_args.
(x_create_tip_frame): Set new frame's 'tooltip' structure
member to true.
(x_hide_tip): Rewrite with additional tests of frames for
liveness and taking into account that for GTK+ tips the
reference frame is now stored in tip_last_frame instead of
tip_frame.
(Fx_show_tip): Handle last_show_tip_args to tip_last_frame,
tip_last_string and tip_last_parms conversion.  For GTK+ store
FRAME argument in tip_last-frame.
(syms_of_xfns): staticpro tip_last_frame, tip_last_string
and tip_last_parms instead of last_show_tip_args.
* src/xterm.c (x_update_begin, handle_one_xevent, x_new_font)
(x_set_window_size): Rewrite with new macro FRAME_TOOLTIP_P.
* src/xterm.h (tip_window): Add external declaration.
* etc/NEWS: Mention new modeline tooltips behavior.

12 files changed, 295 insertions, 221 deletions

diff --git a/src/dispextern.h b/src/dispextern.h
index 25bd6b24f22..441361b4083 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -3452,15 +3452,6 @@ void gamma_correct (struct frame *, COLORREF *);
 void x_implicitly_set_name (struct frame *, Lisp_Object, Lisp_Object);
 void x_change_tool_bar_height (struct frame *f, int);
 
-/* The frame used to display a tooltip.
-
-   Note: In a GTK build with non-zero x_gtk_use_system_tooltips, this
-   variable holds the frame that shows the tooltip, not the frame of
-   the tooltip itself, so checking whether a frame is a tooltip frame
-   cannot just compare the frame to what this variable holds.  */
-extern Lisp_Object tip_frame;
-
-extern Window tip_window;
 extern frame_parm_handler x_frame_parm_handlers[];
 
 extern void start_hourglass (void);
diff --git a/src/frame.c b/src/frame.c
index 1c6289a6b6c..9b560808128 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -832,6 +832,7 @@ make_frame (bool mini_p)
   f->no_focus_on_map = false;
   f->no_accept_focus = false;
   f->z_group = z_group_none;
+  f->tooltip = false;
 #if ! defined (USE_GTK) && ! defined (HAVE_NS)
   f->last_tool_bar_item = -1;
 #endif
@@ -1467,20 +1468,21 @@ DEFUN ("selected-frame", Fselected_frame, Sselected_frame, 0, 0, 0,
 
 DEFUN ("frame-list", Fframe_list, Sframe_list,
        0, 0, 0,
-       doc: /* Return a list of all live frames.  */)
+       doc: /* Return a list of all live frames.
+The return value does not include any tooltip frame.  */)
   (void)
 {
-  Lisp_Object frames;
-  frames = Fcopy_sequence (Vframe_list);
 #ifdef HAVE_WINDOW_SYSTEM
-  if (FRAMEP (tip_frame)
-#ifdef USE_GTK
-      && !NILP (Fframe_parameter (tip_frame, Qtooltip))
-#endif
-      )
-    frames = Fdelq (tip_frame, frames);
-#endif
-  return frames;
+  Lisp_Object list = Qnil, tail, frame;
+
+  FOR_EACH_FRAME (tail, frame)
+    if (!FRAME_TOOLTIP_P (XFRAME (frame)))
+      list = Fcons (frame, list);
+  /* Reverse list for consistency with the !HAVE_WINDOW_SYSTEM case.  */
+  return Fnreverse (list);
+#else /* !HAVE_WINDOW_SYSTEM */
+  return Fcopy_sequence (Vframe_list);
+#endif /* HAVE_WINDOW_SYSTEM */
 }
 
 DEFUN ("frame-parent", Fframe_parent, Sframe_parent,
@@ -1711,7 +1713,8 @@ DEFUN ("last-nonminibuffer-frame", Flast_nonminibuf_frame,
  * other_frames:
  *
  * Return true if there exists at least one visible or iconified frame
- * but F.  Return false otherwise.
+ * but F.  Tooltip frames do not qualify as candidates.  Return false
+ * if no such frame exists.
  *
  * INVISIBLE true means we are called from make_frame_invisible where
  * such a frame must be visible or iconified.  INVISIBLE nil means we
@@ -1725,7 +1728,6 @@ static bool
 other_frames (struct frame *f, bool invisible, bool force)
 {
   Lisp_Object frames, frame, frame1;
-  struct frame *f1;
   Lisp_Object minibuffer_window = FRAME_MINIBUF_WINDOW (f);
 
   XSETFRAME (frame, f);
@@ -1735,7 +1737,8 @@ other_frames (struct frame *f, bool invisible, bool force)
 
   FOR_EACH_FRAME (frames, frame1)
     {
-      f1 = XFRAME (frame1);
+      struct frame *f1 = XFRAME (frame1);
+
       if (f != f1)
         {
           /* Verify that we can still talk to the frame's X window, and
@@ -1744,7 +1747,7 @@ other_frames (struct frame *f, bool invisible, bool force)
           if (FRAME_WINDOW_P (f1))
             x_sync (f1);
 #endif
-          if (NILP (Fframe_parameter (frame1, Qtooltip))
+          if (!FRAME_TOOLTIP_P (f1)
               /* Tooltips and child frames count neither for
                  invisibility nor for deletions.  */
               && !FRAME_PARENT_FRAME (f1)
@@ -1877,7 +1880,7 @@ delete_frame (Lisp_Object frame, Lisp_Object force)
         }
     }
 
-  is_tooltip_frame = !NILP (Fframe_parameter (frame, Qtooltip));
+  is_tooltip_frame = FRAME_TOOLTIP_P (f);
 
   /* Run `delete-frame-functions' unless FORCE is `noelisp' or
      frame is a tooltip.  FORCE is set to `noelisp' when handling
@@ -1925,27 +1928,31 @@ delete_frame (Lisp_Object frame, Lisp_Object force)
          Do not call next_frame here because it may loop forever.
          See https://debbugs.gnu.org/cgi/bugreport.cgi?bug=15025.  */
       FOR_EACH_FRAME (tail, frame1)
-        if (!EQ (frame, frame1)
-            && NILP (Fframe_parameter (frame1, Qtooltip))
-            && (FRAME_TERMINAL (XFRAME (frame))
-                == FRAME_TERMINAL (XFRAME (frame1)))
-            && FRAME_VISIBLE_P (XFRAME (frame1)))
-         break;
+        {
+          struct frame *f1 = XFRAME (frame1);
+
+          if (!EQ (frame, frame1)
+              && !FRAME_TOOLTIP_P (f1)
+              && FRAME_TERMINAL (f) == FRAME_TERMINAL (f1)
+              && FRAME_VISIBLE_P (f1))
+            break;
+        }
 
       /* If there is none, find *some* other frame.  */
       if (NILP (frame1) || EQ (frame1, frame))
         {
           FOR_EACH_FRAME (tail, frame1)
             {
+              struct frame *f1 = XFRAME (frame1);
+
               if (!EQ (frame, frame1)
-                  && FRAME_LIVE_P (XFRAME (frame1))
-                  && NILP (Fframe_parameter (frame1, Qtooltip)))
+                  && FRAME_LIVE_P (f1)
+                  && !FRAME_TOOLTIP_P (f1))
                 {
-                  /* Do not change a text terminal's top-frame.  */
-                  struct frame *f1 = XFRAME (frame1);
                   if (FRAME_TERMCAP_P (f1) || FRAME_MSDOS_P (f1))
                     {
                       Lisp_Object top_frame = FRAME_TTY (f1)->top_frame;
+
                       if (!EQ (top_frame, frame))
                         frame1 = top_frame;
                     }
diff --git a/src/frame.h b/src/frame.h
index 402d6c0a7b2..2c9c4143886 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -342,6 +342,9 @@ struct frame
   ENUM_BF (output_method) output_method : 3;
 
 #ifdef HAVE_WINDOW_SYSTEM
+  /* True if this frame is a tooltip frame.  */
+  bool_bf tooltip : 1;
+
   /* See FULLSCREEN_ enum on top.  */
   ENUM_BF (fullscreen_type) want_fullscreen : 4;
 
@@ -351,9 +354,7 @@ struct frame
 
   /* Nonzero if we should actually display horizontal scroll bars on this frame.  */
   bool_bf horizontal_scroll_bars : 1;
-#endif /* HAVE_WINDOW_SYSTEM */
 
-#if defined (HAVE_WINDOW_SYSTEM)
   /* True if this is an undecorated frame.  */
   bool_bf undecorated : 1;
 
@@ -967,6 +968,7 @@ default_pixels_per_inch_y (void)
 #define FRAME_Z_GROUP_ABOVE_SUSPENDED(f)        \
   ((f)->z_group == z_group_above_suspended)
 #define FRAME_Z_GROUP_BELOW(f) ((f)->z_group == z_group_below)
+#define FRAME_TOOLTIP_P(f) ((f)->tooltip)
 #ifdef NS_IMPL_COCOA
 #define FRAME_NS_APPEARANCE(f) ((f)->ns_appearance)
 #define FRAME_NS_TRANSPARENT_TITLEBAR(f) ((f)->ns_transparent_titlebar)
@@ -983,6 +985,7 @@ default_pixels_per_inch_y (void)
 #define FRAME_Z_GROUP_NONE(f) ((void) (f), true)
 #define FRAME_Z_GROUP_ABOVE(f) ((void) (f), false)
 #define FRAME_Z_GROUP_BELOW(f) ((void) (f), false)
+#define FRAME_TOOLTIP_P(f) ((void) f, false)
 #endif /* HAVE_WINDOW_SYSTEM */
 
 /* Whether horizontal scroll bars are currently enabled for frame F.  */
diff --git a/src/gtkutil.c b/src/gtkutil.c
index 047417fde84..34c0fcc2650 100644
--- a/src/gtkutil.c
+++ b/src/gtkutil.c
@@ -687,6 +687,7 @@ qttip_cb (GtkWidget  *widget,
       g_signal_connect (x->ttip_lbl, "hierarchy-changed",
                         G_CALLBACK (hierarchy_ch_cb), f);
     }
+
   return FALSE;
 }
 
@@ -713,7 +714,8 @@ xg_prepare_tooltip (struct frame *f,
   GtkRequisition req;
   Lisp_Object encoded_string;
 
-  if (!x->ttip_lbl) return 0;
+  if (!x->ttip_lbl)
+    return FALSE;
 
   block_input ();
   encoded_string = ENCODE_UTF_8 (string);
@@ -745,7 +747,7 @@ xg_prepare_tooltip (struct frame *f,
 
   unblock_input ();
 
-  return 1;
+  return TRUE;
 #endif /* USE_GTK_TOOLTIP */
 }
 
@@ -768,18 +770,18 @@ xg_show_tooltip (struct frame *f, int root_x, int root_y)
 #endif
 }
 
+
 /* Hide tooltip if shown.  Do nothing if not shown.
    Return true if tip was hidden, false if not (i.e. not using
    system tooltips).  */
-
 bool
 xg_hide_tooltip (struct frame *f)
 {
-  bool ret = 0;
 #ifdef USE_GTK_TOOLTIP
   if (f->output_data.x->ttip_window)
     {
       GtkWindow *win = f->output_data.x->ttip_window;
+
       block_input ();
       gtk_widget_hide (GTK_WIDGET (win));
 
@@ -792,10 +794,10 @@ xg_hide_tooltip (struct frame *f)
         }
       unblock_input ();
 
-      ret = 1;
+      return TRUE;
     }
 #endif
-  return ret;
+  return FALSE;
 }
 
 
diff --git a/src/nsfns.m b/src/nsfns.m
index c8b30246268..0f60bb8107f 100644
--- a/src/nsfns.m
+++ b/src/nsfns.m
@@ -2753,10 +2753,6 @@ If omitted or nil, that stands for the selected frame's display.  */)
   return make_number (1 << min (dpyinfo->n_planes, 24));
 }
 
-
-/* Unused dummy def needed for compatibility. */
-Lisp_Object tip_frame;
-
 /* TODO: move to xdisp or similar */
 static void
 compute_tip_xy (struct frame *f,
diff --git a/src/w32fns.c b/src/w32fns.c
index 6e0b3adf160..27c765ed920 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -6423,7 +6423,7 @@ w32_display_monitor_attributes_list (void)
     {
       struct frame *f = XFRAME (frame);
 
-      if (FRAME_W32_P (f) && !EQ (frame, tip_frame))
+      if (FRAME_W32_P (f) && !FRAME_TOOLTIP_P (f))
         {
           HMONITOR monitor =
             monitor_from_window_fn (FRAME_W32_WINDOW (f),
@@ -6510,7 +6510,7 @@ w32_display_monitor_attributes_list_fallback (struct w32_display_info *dpyinfo)
     {
       struct frame *f = XFRAME (frame);
 
-      if (FRAME_W32_P (f) && !EQ (frame, tip_frame))
+      if (FRAME_W32_P (f) && !FRAME_TOOLTIP_P (f))
         frames = Fcons (frame, frames);
     }
   attributes = Fcons (Fcons (Qframes, frames), attributes);
@@ -6916,20 +6916,25 @@ no value of TYPE (always string in the MS Windows case).  */)
 static void compute_tip_xy (struct frame *, Lisp_Object, Lisp_Object,
                             Lisp_Object, int, int, int *, int *);
 
-/* The frame of a currently visible tooltip.  */
-
+/* The frame of the currently visible tooltip.  */
 Lisp_Object tip_frame;
 
-/* If non-nil, a timer started that hides the last tooltip when it
-   fires.  */
+/* The window-system window corresponding to the frame of the
+   currently visible tooltip.  */
+Window tip_window;
 
+/* A timer that hides or deletes the currently visible tooltip when it
+   fires.  */
 Lisp_Object tip_timer;
-Window tip_window;
 
-/* If non-nil, a vector of 3 elements containing the last args
-   with which x-show-tip was called.  See there.  */
+/* STRING argument of last `x-show-tip' call.  */
+Lisp_Object tip_last_string;
 
-Lisp_Object last_show_tip_args;
+/* FRAME argument of last `x-show-tip' call.  */
+Lisp_Object tip_last_frame;
+
+/* PARMS argument of last `x-show-tip' call.  */
+Lisp_Object tip_last_parms;
 
 
 static void
@@ -7002,6 +7007,7 @@ x_create_tip_frame (struct w32_display_info *dpyinfo, Lisp_Object parms)
 
   FRAME_FONTSET (f)  = -1;
   fset_icon_name (f, Qnil);
+  f->tooltip = true;
 
 #ifdef GLYPH_DEBUG
   image_cache_refcount =
@@ -7261,7 +7267,17 @@ compute_tip_xy (struct frame *f,
     *root_x = min_x;
 }
 
-/* Hide tooltip.  Delete its frame if DELETE is true.  */
+/**
+ * x_hide_tip:
+ *
+ * Hide currently visible tooltip and cancel its timer.
+ *
+ * This will try to make tooltip_frame invisible (if DELETE is false)
+ * or delete tooltip_frame (if DELETE is true).
+ *
+ * Return Qt if the tooltip was either deleted or made invisible, Qnil
+ * otherwise.
+ */
 static Lisp_Object
 x_hide_tip (bool delete)
 {
@@ -7286,15 +7302,20 @@ x_hide_tip (bool delete)
 
       if (FRAMEP (tip_frame))
         {
-          if (delete)
+          if (FRAME_LIVE_P (XFRAME (tip_frame)))
             {
-              delete_frame (tip_frame, Qnil);
-              tip_frame = Qnil;
+              if (delete)
+                {
+                  delete_frame (tip_frame, Qnil);
+                  tip_frame = Qnil;
+                }
+              else
+                x_make_frame_invisible (XFRAME (tip_frame));
+
+              was_open = Qt;
             }
           else
-            x_make_frame_invisible (XFRAME (tip_frame));
-
-          was_open = Qt;
+            tip_frame = Qnil;
         }
       else
         tip_frame = Qnil;
@@ -7334,7 +7355,8 @@ with offset DY added (default is -10).
 
 A tooltip's maximum size is specified by `x-max-tooltip-size'.
 Text larger than the specified size is clipped.  */)
-  (Lisp_Object string, Lisp_Object frame, Lisp_Object parms, Lisp_Object timeout, Lisp_Object dx, Lisp_Object dy)
+  (Lisp_Object string, Lisp_Object frame, Lisp_Object parms,
+   Lisp_Object timeout, Lisp_Object dx, Lisp_Object dy)
 {
   struct frame *tip_f;
   struct window *w;
@@ -7345,8 +7367,7 @@ Text larger than the specified size is clipped.  */)
   int old_windows_or_buffers_changed = windows_or_buffers_changed;
   ptrdiff_t count = SPECPDL_INDEX ();
   ptrdiff_t count_1;
-  Lisp_Object window, size;
-  Lisp_Object tip_buf;
+  Lisp_Object window, size, tip_buf;
   AUTO_STRING (tip, " *tip*");
 
   specbind (Qinhibit_redisplay, Qt);
@@ -7368,19 +7389,12 @@ Text larger than the specified size is clipped.  */)
   else
     CHECK_NUMBER (dy);
 
-  if (NILP (last_show_tip_args))
-    last_show_tip_args = Fmake_vector (make_number (3), Qnil);
-
   if (FRAMEP (tip_frame) && FRAME_LIVE_P (XFRAME (tip_frame)))
     {
-      Lisp_Object last_string = AREF (last_show_tip_args, 0);
-      Lisp_Object last_frame = AREF (last_show_tip_args, 1);
-      Lisp_Object last_parms = AREF (last_show_tip_args, 2);
-
       if (FRAME_VISIBLE_P (XFRAME (tip_frame))
-          && EQ (frame, last_frame)
-          && !NILP (Fequal_including_properties (last_string, string))
-          && !NILP (Fequal (last_parms, parms)))
+          && EQ (frame, tip_last_frame)
+          && !NILP (Fequal_including_properties (string, tip_last_string))
+          && !NILP (Fequal (parms, tip_last_parms)))
         {
           /* Only DX and DY have changed.  */
           tip_f = XFRAME (tip_frame);
@@ -7414,14 +7428,14 @@ Text larger than the specified size is clipped.  */)
 
           goto start_timer;
         }
-      else if (tooltip_reuse_hidden_frame && EQ (frame, last_frame))
+      else if (tooltip_reuse_hidden_frame && EQ (frame, tip_last_frame))
         {
           bool delete = false;
           Lisp_Object tail, elt, parm, last;
 
           /* Check if every parameter in PARMS has the same value in
-             last_parms.  This may destruct last_parms which, however,
-             will be recreated below.  */
+             tip_last_parms.  This may destruct tip_last_parms
+             which, however, will be recreated below.  */
           for (tail = parms; CONSP (tail); tail = XCDR (tail))
             {
               elt = XCAR (tail);
@@ -7431,7 +7445,7 @@ Text larger than the specified size is clipped.  */)
               if (!EQ (parm, Qleft) && !EQ (parm, Qtop)
                   && !EQ (parm, Qright) && !EQ (parm, Qbottom))
                 {
-                  last = Fassq (parm, last_parms);
+                  last = Fassq (parm, tip_last_parms);
                   if (NILP (Fequal (Fcdr (elt), Fcdr (last))))
                     {
                       /* We lost, delete the old tooltip.  */
@@ -7439,15 +7453,17 @@ Text larger than the specified size is clipped.  */)
                       break;
                     }
                   else
-                    last_parms = call2 (Qassq_delete_all, parm, last_parms);
+                    tip_last_parms =
+                      call2 (Qassq_delete_all, parm, tip_last_parms);
                 }
               else
-                last_parms = call2 (Qassq_delete_all, parm, last_parms);
+                tip_last_parms =
+                  call2 (Qassq_delete_all, parm, tip_last_parms);
             }
 
-          /* Now check if there's a parameter left in last_parms with a
+          /* Now check if there's a parameter left in tip_last_parms with a
              non-nil value.  */
-          for (tail = last_parms; CONSP (tail); tail = XCDR (tail))
+          for (tail = tip_last_parms; CONSP (tail); tail = XCDR (tail))
             {
               elt = XCAR (tail);
               parm = Fcar (elt);
@@ -7468,9 +7484,9 @@ Text larger than the specified size is clipped.  */)
   else
     x_hide_tip (true);
 
-  ASET (last_show_tip_args, 0, string);
-  ASET (last_show_tip_args, 1, frame);
-  ASET (last_show_tip_args, 2, parms);
+  tip_last_frame = frame;
+  tip_last_string = string;
+  tip_last_parms = parms;
 
   /* Block input until the tip has been fully drawn, to avoid crashes
      when drawing tips in menus.  */
@@ -7486,7 +7502,8 @@ Text larger than the specified size is clipped.  */)
       if (NILP (Fassq (Qborder_width, parms)))
         parms = Fcons (Fcons (Qborder_width, make_number (1)), parms);
       if (NILP (Fassq (Qborder_color, parms)))
-        parms = Fcons (Fcons (Qborder_color, build_string ("lightyellow")), parms);
+        parms = Fcons (Fcons (Qborder_color, build_string ("lightyellow")),
+                       parms);
       if (NILP (Fassq (Qbackground_color, parms)))
         parms = Fcons (Fcons (Qbackground_color, build_string ("lightyellow")),
                        parms);
@@ -10695,9 +10712,12 @@ tip frame.  */);
   staticpro (&tip_timer);
   tip_frame = Qnil;
   staticpro (&tip_frame);
-
-  last_show_tip_args = Qnil;
-  staticpro (&last_show_tip_args);
+  tip_last_frame = Qnil;
+  staticpro (&tip_last_frame);
+  tip_last_string = Qnil;
+  staticpro (&tip_last_string);
+  tip_last_parms = Qnil;
+  staticpro (&tip_last_parms);
 
   defsubr (&Sx_file_dialog);
 #ifdef WINDOWSNT
diff --git a/src/w32term.c b/src/w32term.c
index db4ccf58138..137c798c463 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -5569,7 +5569,7 @@ w32_read_socket (struct terminal *terminal,
         struct frame *f = XFRAME (frame);
         /* The tooltip has been drawn already.  Avoid the
            SET_FRAME_GARBAGED below.  */
-        if (EQ (frame, tip_frame))
+        if (FRAME_TOOLTIP_P (f))
           continue;
 
         /* Check "visible" frames and mark each as obscured or not.
@@ -6046,7 +6046,7 @@ x_new_font (struct frame *f, Lisp_Object font_object, int fontset)
       /* Don't change the size of a tip frame; there's no point in
          doing it because it's done in Fx_show_tip, and it leads to
          problems because the tip frame has no widget.  */
-      if (NILP (tip_frame) || XFRAME (tip_frame) != f)
+      if (!FRAME_TOOLTIP_P (f))
         adjust_frame_size (f, FRAME_COLS (f) * FRAME_COLUMN_WIDTH (f),
                            FRAME_LINES (f) * FRAME_LINE_HEIGHT (f), 3,
                            false, Qfont);
diff --git a/src/w32term.h b/src/w32term.h
index e500b730ead..c69bebeebdd 100644
--- a/src/w32term.h
+++ b/src/w32term.h
@@ -817,6 +817,8 @@ extern struct window *w32_system_caret_window;
 extern int w32_system_caret_hdr_height;
 extern int w32_system_caret_mode_height;
 
+extern Window tip_window;
+
 #ifdef _MSC_VER
 #ifndef EnumSystemLocales
 /* MSVC headers define these only for _WIN32_WINNT >= 0x0500.  */
diff --git a/src/xdisp.c b/src/xdisp.c
index 59fa00e1af4..d2bb47fdabd 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -11866,7 +11866,7 @@ x_consider_frame_title (Lisp_Object frame)
   if ((FRAME_WINDOW_P (f)
        || FRAME_MINIBUF_ONLY_P (f)
        || f->explicit_name)
-      && NILP (Fframe_parameter (frame, Qtooltip)))
+      && !FRAME_TOOLTIP_P (f))
     {
       /* Do we have more than one visible frame on this X display?  */
       Lisp_Object tail, other_frame, fmt;
@@ -11883,8 +11883,8 @@ x_consider_frame_title (Lisp_Object frame)
           if (tf != f
               && FRAME_KBOARD (tf) == FRAME_KBOARD (f)
               && !FRAME_MINIBUF_ONLY_P (tf)
-              && !EQ (other_frame, tip_frame)
               && !FRAME_PARENT_FRAME (tf)
+              && !FRAME_TOOLTIP_P (tf)
               && (FRAME_VISIBLE_P (tf) || FRAME_ICONIFIED_P (tf)))
             break;
         }
@@ -11953,13 +11953,6 @@ prepare_menu_bars (void)
 {
   bool all_windows = windows_or_buffers_changed || update_mode_lines;
   bool some_windows = REDISPLAY_SOME_P ();
-  Lisp_Object tooltip_frame;
-
-#ifdef HAVE_WINDOW_SYSTEM
-  tooltip_frame = tip_frame;
-#else
-  tooltip_frame = Qnil;
-#endif
 
   if (FUNCTIONP (Vpre_redisplay_function))
     {
@@ -12000,7 +11993,7 @@ prepare_menu_bars (void)
               && !XBUFFER (w->contents)->text->redisplay)
             continue;
 
-          if (!EQ (frame, tooltip_frame)
+          if (!FRAME_TOOLTIP_P (f)
               && !FRAME_PARENT_FRAME (f)
               && (FRAME_ICONIFIED_P (f)
                   || FRAME_VISIBLE_P (f) == 1
@@ -12038,7 +12031,7 @@ prepare_menu_bars (void)
           struct window *w = XWINDOW (FRAME_SELECTED_WINDOW (f));
 
           /* Ignore tooltip frame.  */
-          if (EQ (frame, tooltip_frame))
+          if (FRAME_TOOLTIP_P (f))
             continue;
 
           if (some_windows
@@ -21160,13 +21153,7 @@ should_produce_line_number (struct it *it)
 
 #ifdef HAVE_WINDOW_SYSTEM
   /* Don't display line number in tooltip frames.  */
-  if (FRAMEP (tip_frame) && EQ (WINDOW_FRAME (it->w), tip_frame)
-#ifdef USE_GTK
-      /* GTK builds store in tip_frame the frame that shows the tip,
-         so we need an additional test.  */
-      && !NILP (Fframe_parameter (tip_frame, Qtooltip))
-#endif
-      )
+  if (FRAME_TOOLTIP_P (XFRAME (WINDOW_FRAME (it->w))))
     return false;
 #endif
 
@@ -30841,9 +30828,11 @@ note_mode_line_or_margin_highlight (Lisp_Object window, int x, int y,
                 = buffer_local_value (Qmode_line_default_help_echo,
                                       w->contents);
 
-              if (STRINGP (default_help))
+              if (FUNCTIONP (default_help) || STRINGP (default_help))
                 {
-                  help_echo_string = default_help;
+                  help_echo_string = (FUNCTIONP (default_help)
+                                      ? safe_call1 (default_help, window)
+                                      : default_help);
                   XSETWINDOW (help_echo_window, w);
                   help_echo_object = Qnil;
                   help_echo_pos = -1;
diff --git a/src/xfns.c b/src/xfns.c
index 12b7d83c383..43c55cca643 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -4612,8 +4612,9 @@ x_make_monitor_attribute_list (struct MonitorInfo *monitors,
     {
       struct frame *f = XFRAME (frame);
 
-      if (FRAME_X_P (f) && FRAME_DISPLAY_INFO (f) == dpyinfo
-          && !EQ (frame, tip_frame))
+      if (FRAME_X_P (f)
+          && FRAME_DISPLAY_INFO (f) == dpyinfo
+          && !FRAME_TOOLTIP_P (f))
         {
           int i = x_get_monitor_for_frame (f, monitors, n_monitors);
           ASET (monitor_frames, i, Fcons (frame, AREF (monitor_frames, i)));
@@ -4914,12 +4915,9 @@ Internal use only, use `display-monitor-attributes-list' instead.  */)
     {
       struct frame *f = XFRAME (frame);
 
-      if (FRAME_X_P (f) && FRAME_DISPLAY_INFO (f) == dpyinfo
-          && !(EQ (frame, tip_frame)
-#ifdef USE_GTK
-               && !NILP (Fframe_parameter (tip_frame, Qtooltip))
-#endif
-               ))
+      if (FRAME_X_P (f)
+          && FRAME_DISPLAY_INFO (f) == dpyinfo
+          && !FRAME_TOOLTIP_P (f))
         {
           GdkWindow *gwin = gtk_widget_get_window (FRAME_GTK_WIDGET (f));
 
@@ -6052,22 +6050,27 @@ Otherwise, the return value is a vector with the following fields:
  ***********************************************************************/
 
 static void compute_tip_xy (struct frame *, Lisp_Object, Lisp_Object,
-                            Lisp_Object, int, int, int *, int *);
-
-/* The frame of a currently visible tooltip.  */
+                            Lisp_Object, int, int, int *, int *);
 
+/* The frame of the currently visible tooltip.  */
 Lisp_Object tip_frame;
 
-/* If non-nil, a timer started that hides the last tooltip when it
+/* The window-system window corresponding to the frame of the
+   currently visible tooltip.  */
+Window tip_window;
+
+/* A timer that hides or deletes the currently visible tooltip when it
    fires.  */
+Lisp_Object tip_timer;
 
-static Lisp_Object tip_timer;
-Window tip_window;
+/* STRING argument of last `x-show-tip' call.  */
+Lisp_Object tip_last_string;
 
-/* If non-nil, a vector of 3 elements containing the last args
-   with which x-show-tip was called.  See there.  */
+/* FRAME argument of last `x-show-tip' call.  */
+Lisp_Object tip_last_frame;
 
-static Lisp_Object last_show_tip_args;
+/* PARMS argument of last `x-show-tip' call.  */
+Lisp_Object tip_last_parms;
 
 
 static void
@@ -6141,6 +6144,7 @@ x_create_tip_frame (struct x_display_info *dpyinfo, Lisp_Object parms)
   f->output_data.x->white_relief.pixel = -1;
   f->output_data.x->black_relief.pixel = -1;
 
+  f->tooltip = true;
   fset_icon_name (f, Qnil);
   FRAME_DISPLAY_INFO (f) = dpyinfo;
   f->output_data.x->parent_desc = FRAME_DISPLAY_INFO (f)->root_window;
@@ -6405,7 +6409,9 @@ x_create_tip_frame (struct x_display_info *dpyinfo, Lisp_Object parms)
    the display in *ROOT_X, and *ROOT_Y.  */
 
 static void
-compute_tip_xy (struct frame *f, Lisp_Object parms, Lisp_Object dx, Lisp_Object dy, int width, int height, int *root_x, int *root_y)
+compute_tip_xy (struct frame *f,
+                Lisp_Object parms, Lisp_Object dx, Lisp_Object dy,
+                int width, int height, int *root_x, int *root_y)
 {
   Lisp_Object left, top, right, bottom;
   int win_x, win_y;
@@ -6502,7 +6508,19 @@ compute_tip_xy (struct frame *f, Lisp_Object parms, Lisp_Object dx, Lisp_Object
 }
 
 
-/* Hide tooltip.  Delete its frame if DELETE is true.  */
+/**
+ * x_hide_tip:
+ *
+ * Hide currently visible tooltip and cancel its timer.
+ *
+ * If GTK+ system tooltips are used, this will try to hide the tooltip
+ * referenced by the x_output structure of tooltip_last_frame.  For
+ * Emacs tooltips this will try to make tooltip_frame invisible (if
+ * DELETE is false) or delete tooltip_frame (if DELETE is true).
+ *
+ * Return Qt if the tooltip was either deleted or made invisible, Qnil
+ * otherwise.
+ */
 static Lisp_Object
 x_hide_tip (bool delete)
 {
@@ -6512,10 +6530,17 @@ x_hide_tip (bool delete)
       tip_timer = Qnil;
     }
 
-
-  if (NILP (tip_frame)
-      || (!delete && FRAMEP (tip_frame)
-          && !FRAME_VISIBLE_P (XFRAME (tip_frame))))
+#ifdef USE_GTK
+  /* The GTK+ system tooltip window can be found via the x_output
+     structure of tip_last_frame, if it still exists.  */
+  if (x_gtk_use_system_tooltips && NILP (tip_last_frame))
+    return Qnil;
+  else if (!x_gtk_use_system_tooltips
+           && (NILP (tip_frame)
+               || (!delete
+                   && FRAMEP (tip_frame)
+                   && FRAME_LIVE_P (XFRAME (tip_frame))
+                   && !FRAME_VISIBLE_P (XFRAME (tip_frame)))))
     return Qnil;
   else
     {
@@ -6526,61 +6551,114 @@ x_hide_tip (bool delete)
       specbind (Qinhibit_redisplay, Qt);
       specbind (Qinhibit_quit, Qt);
 
-#ifdef USE_GTK
-      {
-        /* When using system tooltip, tip_frame is the Emacs frame on
-           which the tip is shown.  */
-        struct frame *f = XFRAME (tip_frame);
-
-        if (FRAME_LIVE_P (f) && xg_hide_tooltip (f))
-          {
-            tip_frame = Qnil;
-            was_open = Qt;
-          }
-      }
-#endif
+      if (x_gtk_use_system_tooltips)
+        {
+          /* The GTK+ system tooltip window is stored in the x_output
+             structure of tip_last_frame.  */
+          struct frame *f = XFRAME (tip_last_frame);
 
-      if (FRAMEP (tip_frame))
+          if (FRAME_LIVE_P (f))
+            {
+              if (xg_hide_tooltip (f))
+                was_open = Qt;
+            }
+          else
+            tip_last_frame = Qnil;
+        }
+      else
         {
-          if (delete)
+          if (FRAMEP (tip_frame))
             {
-              delete_frame (tip_frame, Qnil);
-              tip_frame = Qnil;
+              struct frame *f = XFRAME (tip_frame);
+
+              if (FRAME_LIVE_P (f))
+                {
+                  if (delete)
+                    {
+                      delete_frame (tip_frame, Qnil);
+                      tip_frame = Qnil;
+                    }
+                  else
+                    x_make_frame_invisible (f);
+
+                  was_open = Qt;
+                }
+              else
+                tip_frame = Qnil;
             }
           else
-            x_make_frame_invisible (XFRAME (tip_frame));
+            tip_frame = Qnil;
+        }
+
+      return unbind_to (count, was_open);
+    }
+#else /* not USE_GTK */
+  if (NILP (tip_frame)
+      || (!delete
+          && FRAMEP (tip_frame)
+          && FRAME_LIVE_P (XFRAME (tip_frame))
+          && !FRAME_VISIBLE_P (XFRAME (tip_frame))))
+    return Qnil;
+  else
+    {
+      ptrdiff_t count;
+      Lisp_Object was_open = Qnil;
+
+      count = SPECPDL_INDEX ();
+      specbind (Qinhibit_redisplay, Qt);
+      specbind (Qinhibit_quit, Qt);
+
+      if (FRAMEP (tip_frame))
+        {
+          struct frame *f = XFRAME (tip_frame);
 
-          was_open = Qt;
+          if (FRAME_LIVE_P (f))
+            {
+              if (delete)
+                {
+                  delete_frame (tip_frame, Qnil);
+                  tip_frame = Qnil;
+                }
+              else
+                x_make_frame_invisible (XFRAME (tip_frame));
 
 #ifdef USE_LUCID
-          /* Bloodcurdling hack alert: The Lucid menu bar widget's
-             redisplay procedure is not called when a tip frame over
-             menu items is unmapped.  Redisplay the menu manually...  */
-          {
-            Widget w;
-            struct frame *f = SELECTED_FRAME ();
-            if (FRAME_X_P (f) && FRAME_LIVE_P (f))
+              /* Bloodcurdling hack alert: The Lucid menu bar widget's
+                 redisplay procedure is not called when a tip frame over
+                 menu items is unmapped.  Redisplay the menu manually...  */
               {
-                w = f->output_data.x->menubar_widget;
+                Widget w;
+                struct frame *f = SELECTED_FRAME ();
 
-                if (!DoesSaveUnders (FRAME_DISPLAY_INFO (f)->screen)
-                    && w != NULL)
+                if (FRAME_X_P (f) && FRAME_LIVE_P (f))
                   {
-                    block_input ();
-                    xlwmenu_redisplay (w);
-                    unblock_input ();
+                    w = f->output_data.x->menubar_widget;
+
+                    if (!DoesSaveUnders (FRAME_DISPLAY_INFO (f)->screen)
+                        && w != NULL)
+                      {
+                        block_input ();
+                        xlwmenu_redisplay (w);
+                        unblock_input ();
+                      }
                   }
               }
-          }
 #endif /* USE_LUCID */
+
+              was_open = Qt;
+            }
+          else
+            tip_frame = Qnil;
         }
       else
         tip_frame = Qnil;
 
       return unbind_to (count, was_open);
     }
+#endif /* USE_GTK */
 }
 
+
 DEFUN ("x-show-tip", Fx_show_tip, Sx_show_tip, 1, 6, 0,
        doc: /* Show STRING in a "tooltip" window on frame FRAME.
 A tooltip window is a small X window displaying a string.
@@ -6611,7 +6689,8 @@ with offset DY added (default is -10).
 
 A tooltip's maximum size is specified by `x-max-tooltip-size'.
 Text larger than the specified size is clipped.  */)
-  (Lisp_Object string, Lisp_Object frame, Lisp_Object parms, Lisp_Object timeout, Lisp_Object dx, Lisp_Object dy)
+  (Lisp_Object string, Lisp_Object frame, Lisp_Object parms,
+   Lisp_Object timeout, Lisp_Object dx, Lisp_Object dy)
 {
   struct frame *f, *tip_f;
   struct window *w;
@@ -6622,8 +6701,7 @@ Text larger than the specified size is clipped.  */)
   int old_windows_or_buffers_changed = windows_or_buffers_changed;
   ptrdiff_t count = SPECPDL_INDEX ();
   ptrdiff_t count_1;
-  Lisp_Object window, size;
-  Lisp_Object tip_buf;
+  Lisp_Object window, size, tip_buf;
   AUTO_STRING (tip, " *tip*");
 
   specbind (Qinhibit_redisplay, Qt);
@@ -6662,36 +6740,27 @@ Text larger than the specified size is clipped.  */)
         {
           compute_tip_xy (f, parms, dx, dy, width, height, &root_x, &root_y);
           xg_show_tooltip (f, root_x, root_y);
-          /* This is used in Fx_hide_tip.  */
-          XSETFRAME (tip_frame, f);
+          tip_last_frame = frame;
         }
+
       unblock_input ();
       if (ok) goto start_timer;
     }
 #endif /* USE_GTK */
 
-  if (NILP (last_show_tip_args))
-    last_show_tip_args = Fmake_vector (make_number (3), Qnil);
-
   if (FRAMEP (tip_frame) && FRAME_LIVE_P (XFRAME (tip_frame)))
     {
-      Lisp_Object last_string = AREF (last_show_tip_args, 0);
-      Lisp_Object last_frame = AREF (last_show_tip_args, 1);
-      Lisp_Object last_parms = AREF (last_show_tip_args, 2);
-
       if (FRAME_VISIBLE_P (XFRAME (tip_frame))
-          && EQ (frame, last_frame)
-          && !NILP (Fequal_including_properties (last_string, string))
-          && !NILP (Fequal (last_parms, parms)))
+          && EQ (frame, tip_last_frame)
+          && !NILP (Fequal_including_properties (tip_last_string, string))
+          && !NILP (Fequal (tip_last_parms, parms)))
         {
           /* Only DX and DY have changed.  */
           tip_f = XFRAME (tip_frame);
           if (!NILP (tip_timer))
             {
-              Lisp_Object timer = tip_timer;
-
+              call1 (Qcancel_timer, tip_timer);
               tip_timer = Qnil;
-              call1 (Qcancel_timer, timer);
             }
 
           block_input ();
@@ -6703,15 +6772,14 @@ Text larger than the specified size is clipped.  */)
 
           goto start_timer;
         }
-      else if (tooltip_reuse_hidden_frame && EQ (frame, last_frame))
+      else if (tooltip_reuse_hidden_frame && EQ (frame, tip_last_frame))
         {
           bool delete = false;
           Lisp_Object tail, elt, parm, last;
 
           /* Check if every parameter in PARMS has the same value in
-             last_parms unless it should be ignored by means of
-             Vtooltip_reuse_hidden_frame_parameters.  This may destruct
-             last_parms which, however, will be recreated below.  */
+             tip_last_parms.  This may destruct tip_last_parms which,
+             however, will be recreated below.  */
           for (tail = parms; CONSP (tail); tail = XCDR (tail))
             {
               elt = XCAR (tail);
@@ -6721,7 +6789,7 @@ Text larger than the specified size is clipped.  */)
               if (!EQ (parm, Qleft) && !EQ (parm, Qtop)
                   && !EQ (parm, Qright) && !EQ (parm, Qbottom))
                 {
-                  last = Fassq (parm, last_parms);
+                  last = Fassq (parm, tip_last_parms);
                   if (NILP (Fequal (Fcdr (elt), Fcdr (last))))
                     {
                       /* We lost, delete the old tooltip.  */
@@ -6729,17 +6797,18 @@ Text larger than the specified size is clipped.  */)
                       break;
                     }
                   else
-                    last_parms = call2 (Qassq_delete_all, parm, last_parms);
+                    tip_last_parms =
+                      call2 (Qassq_delete_all, parm, tip_last_parms);
                 }
               else
-                last_parms = call2 (Qassq_delete_all, parm, last_parms);
+                tip_last_parms =
+                  call2 (Qassq_delete_all, parm, tip_last_parms);
             }
 
-          /* Now check if every parameter in what is left of last_parms
-             with a non-nil value has an association in PARMS unless it
-             should be ignored by means of
-             Vtooltip_reuse_hidden_frame_parameters.  */
-          for (tail = last_parms; CONSP (tail); tail = XCDR (tail))
+          /* Now check if every parameter in what is left of
+             tip_last_parms with a non-nil value has an association in
+             PARMS.  */
+          for (tail = tip_last_parms; CONSP (tail); tail = XCDR (tail))
             {
               elt = XCAR (tail);
               parm = Fcar (elt);
@@ -6760,9 +6829,9 @@ Text larger than the specified size is clipped.  */)
   else
     x_hide_tip (true);
 
-  ASET (last_show_tip_args, 0, string);
-  ASET (last_show_tip_args, 1, frame);
-  ASET (last_show_tip_args, 2, parms);
+  tip_last_frame = frame;
+  tip_last_string = string;
+  tip_last_parms = parms;
 
   if (!FRAMEP (tip_frame) || !FRAME_LIVE_P (XFRAME (tip_frame)))
     {
@@ -7823,7 +7892,6 @@ When using Gtk+ tooltips, the tooltip face is not used.  */);
   defsubr (&Sx_display_list);
   defsubr (&Sx_synchronize);
   defsubr (&Sx_backspace_delete_keys_p);
-
   defsubr (&Sx_show_tip);
   defsubr (&Sx_hide_tip);
   defsubr (&Sx_double_buffered_p);
@@ -7831,9 +7899,12 @@ When using Gtk+ tooltips, the tooltip face is not used.  */);
   staticpro (&tip_timer);
   tip_frame = Qnil;
   staticpro (&tip_frame);
-
-  last_show_tip_args = Qnil;
-  staticpro (&last_show_tip_args);
+  tip_last_frame = Qnil;
+  staticpro (&tip_last_frame);
+  tip_last_string = Qnil;
+  staticpro (&tip_last_string);
+  tip_last_parms = Qnil;
+  staticpro (&tip_last_parms);
 
   defsubr (&Sx_uses_old_gtk_dialog);
 #if defined (USE_MOTIF) || defined (USE_GTK)
diff --git a/src/xterm.c b/src/xterm.c
index f771631dafa..0a2068d7f30 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -996,12 +996,7 @@ static void
 x_update_begin (struct frame *f)
 {
 #ifdef USE_CAIRO
-  if (! NILP (tip_frame) && XFRAME (tip_frame) == f
-      && ! FRAME_VISIBLE_P (f)
-#ifdef USE_GTK
-      && !NILP (Fframe_parameter (tip_frame, Qtooltip))
-#endif
-      )
+  if (FRAME_TOOLTIP_P (f) && !FRAME_VISIBLE_P (f))
     return;
 
   if (! FRAME_CR_SURFACE (f))
@@ -8091,7 +8086,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
       /* Redo the mouse-highlight after the tooltip has gone.  */
       if (event->xunmap.window == tip_window)
         {
-          tip_window = 0;
+          tip_window = None;
           x_redo_mouse_highlight (dpyinfo);
         }
 
@@ -8733,7 +8728,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
 
 #ifdef USE_X_TOOLKIT
           /* Tip frames are pure X window, set size for them.  */
-          if (! NILP (tip_frame) && XFRAME (tip_frame) == f)
+          if (FRAME_TOOLTIP_P (f))
             {
               if (FRAME_PIXEL_HEIGHT (f) != configureEvent.xconfigure.height
                   || FRAME_PIXEL_WIDTH (f) != configureEvent.xconfigure.width)
@@ -9971,11 +9966,7 @@ x_new_font (struct frame *f, Lisp_Object font_object, int fontset)
       /* Don't change the size of a tip frame; there's no point in
          doing it because it's done in Fx_show_tip, and it leads to
          problems because the tip frame has no widget.  */
-      if (NILP (tip_frame) || XFRAME (tip_frame) != f
-#ifdef USE_GTK
-          || NILP (Fframe_parameter (tip_frame, Qtooltip))
-#endif
-          )
+      if (!FRAME_TOOLTIP_P (f))
         {
           adjust_frame_size (f, FRAME_COLS (f) * FRAME_COLUMN_WIDTH (f),
                              FRAME_LINES (f) * FRAME_LINE_HEIGHT (f), 3,
@@ -11204,7 +11195,7 @@ x_set_window_size (struct frame *f, bool change_gravity,
   /* The following breaks our calculations.  If it's really needed,
      think of something else.  */
 #if false
-  if (NILP (tip_frame) || XFRAME (tip_frame) != f)
+  if (!FRAME_TOOLTIP_P (f))
     {
       int text_width, text_height;
 
diff --git a/src/xterm.h b/src/xterm.h
index f73dd0e25ab..1849a5c9535 100644
--- a/src/xterm.h
+++ b/src/xterm.h
@@ -503,6 +503,8 @@ extern bool x_display_ok (const char *);
 
 extern void select_visual (struct x_display_info *);
 
+extern Window tip_window;
+
 /* Each X frame object points to its own struct x_output object
    in the output_data.x field.  The x_output structure contains
    the information that is specific to X windows.  */