Fix related menubutton issues on linux and Windows.

8 files changed, 231 insertions, 188 deletions

diff --git a/doc/menu.n b/doc/menu.n
index ac60e65..338ce6a 100644
--- a/doc/menu.n
+++ b/doc/menu.n
@@ -470,18 +470,19 @@ a menu entry does not automatically unpost the menu;  the default
 bindings normally take care of this before invoking the \fBinvoke\fR
 widget command.
 .TP
-\fIpathName \fBpost \fIx y\fR
+\fIpathName \fBpost \fIx y\fR ?\fIindex\fR?
 .
 Arrange for the menu to be displayed on the screen at the root-window
-coordinates given by \fIx\fR and \fIy\fR.  These coordinates are
-adjusted if necessary to guarantee that the entire menu is visible on
-the screen.  This command normally returns an empty string.
-If the \fB\-postcommand\fR option has been specified, then its value is
-executed as a Tcl script before posting the menu and the result of
-that script is returned as the result of the \fBpost\fR widget
-command.
-If an error returns while executing the command, then the error is
-returned without posting the menu.
+coordinates given by \fIx\fR and \fIy\fR.  If an index is specified
+the menu will be located so that the entry with that index is
+displayed at the point.  These coordinates are adjusted if necessary to
+guarantee that the entire menu is visible on the screen.  This command
+normally returns an empty string.  If the \fB\-postcommand\fR option
+has been specified, then its value is executed as a Tcl script before
+posting the menu and the result of that script is returned as the
+result of the \fBpost\fR widget command.  If an error returns while
+executing the command, then the error is returned without posting the
+menu.
 .TP
 \fIpathName \fBpostcascade \fIindex\fR
 .
diff --git a/generic/tkMenu.c b/generic/tkMenu.c
index 26ffc88..f1ea8ff 100644
--- a/generic/tkMenu.c
+++ b/generic/tkMenu.c
@@ -870,32 +870,46 @@ MenuWidgetObjCmd(
 	break;
     }
     case MENU_POST: {
-	int x, y;
+	int x, y, entry = -1;
 
-	if (objc != 4) {
-	    Tcl_WrongNumArgs(interp, 2, objv, "x y");
+	if (objc != 4 && objc != 5) {
+	    Tcl_WrongNumArgs(interp, 2, objv, "x y ?entry?");
 	    goto error;
 	}
 	if ((Tcl_GetIntFromObj(interp, objv[2], &x) != TCL_OK)
 		|| (Tcl_GetIntFromObj(interp, objv[3], &y) != TCL_OK)) {
 	    goto error;
 	}
+	if (objc == 5) {
+	    if (menuPtr->menuType == TEAROFF_MENU) {
+		Tcl_AppendResult(interp,
+		    "the index option is invalid for tearoff menus", NULL);
+		return TCL_ERROR;
+	    }
+	    if (Tcl_GetIntFromObj(interp, objv[4], &entry) != TCL_OK) {
+		goto error;
+	    }
+	}
 
 	/*
-	 * Tearoff menus are posted differently on Mac and Windows than
-	 * non-tearoffs. TkpPostMenu does not actually map the menu's window
-	 * on those platforms, and popup menus have to be handled specially.
-         * Also, menubar menues are not intended to be posted (bug 1567681,
-         * 2160206).
+	 * Tearoff menus are the same as ordinary menus on the Mac and are
+	 * posted differently on Windows than non-tearoffs. TkpPostMenu
+	 * does not actually map the menu's window on those platforms, and
+	 * popup menus have to be handled specially.  Also, menubar menus are
+	 * not intended to be posted (bug 1567681, 2160206).
 	 */
 
 	if (menuPtr->menuType == MENUBAR) {
             Tcl_AppendResult(interp, "a menubar menu cannot be posted", NULL);
             return TCL_ERROR;
         } else if (menuPtr->menuType != TEAROFF_MENU) {
-	    result = TkpPostMenu(interp, menuPtr, x, y);
+	    result = TkpPostMenu(interp, menuPtr, x, y, entry);
 	} else {
+#ifdef TK_MAC_OSX
+	    result = TkpPostMenu(interp, menuPtr, x, y, entry);
+#else
 	    result = TkPostTearoffMenu(interp, menuPtr, x, y);
+#endif
 	}
 	break;
     }
diff --git a/generic/tkMenu.h b/generic/tkMenu.h
index bac51aa..92bf8b2 100644
--- a/generic/tkMenu.h
+++ b/generic/tkMenu.h
@@ -543,7 +543,7 @@ MODULE_SCOPE void	TkpMenuInit(void);
 MODULE_SCOPE int	TkpMenuNewEntry(TkMenuEntry *mePtr);
 MODULE_SCOPE int	TkpNewMenu(TkMenu *menuPtr);
 MODULE_SCOPE int	TkpPostMenu(Tcl_Interp *interp, TkMenu *menuPtr,
-			    int x, int y);
+			    int x, int y, int entry);
 MODULE_SCOPE void	TkpSetWindowMenuBar(Tk_Window tkwin, TkMenu *menuPtr);
 
 #endif /* _TKMENU */
diff --git a/library/menu.tcl b/library/menu.tcl
index a406ae3..cdfcc13 100644
--- a/library/menu.tcl
+++ b/library/menu.tcl
@@ -234,6 +234,7 @@ proc ::tk::MbLeave w {
     }
 }
 
+
 # ::tk::MbPost --
 # Given a menubutton, this procedure does all the work of posting
 # its associated menu and unposting any other menu that is currently
@@ -274,124 +275,25 @@ proc ::tk::MbPost {w {x {}} {y {}}} {
     if {[tk windowingsystem] ne "aqua"} {
 	set Priv(relief) [$w cget -relief]
 	$w configure -relief raised
-	set xoffset {0 0 0 0 0}
-	set yoffset {0 0 0 0 0}
     } else {
 	$w configure -state active
-	# Compensate for offsets created by the macOS window manager.
-	set xoffset {9 9 18 9 0}
-	set yoffset {6 13 13 13 9}
     }
 
     set Priv(postedMb) $w
     set Priv(focus) [focus]
     $menu activate none
     GenerateMenuSelect $menu
-
-    # If this looks like an option menubutton then post the menu so
-    # that the current entry is on top of the mouse.  Otherwise post
-    # the menu just below the menubutton, as for a pull-down.
-
     update idletasks
-    if {[catch {
-	switch [$w cget -direction] {
-	    above {
-		set x [expr {[winfo rootx $w]}]
-		set y [expr {[winfo rooty $w] - [winfo reqheight $menu]}]
-		# if we go offscreen to the top, show as 'below'
-		if {$y < [winfo vrooty $w]} {
-		    set y [expr {[winfo vrooty $w] + [winfo rooty $w] + [winfo reqheight $w]}]
-		}
-		incr x [lindex $xoffset 0]
-		incr y [lindex $yoffset 0]
-		PostOverPoint $menu $x $y
-	    }
-	    below {
-		set x [expr {[winfo rootx $w]}]
-		set y [expr {[winfo rooty $w] + [winfo height $w]}]
-		# if we go offscreen to the bottom, show as 'above'
-		set mh [winfo reqheight $menu]
-		if {($y + $mh) > ([winfo vrooty $w] + [winfo vrootheight $w])} {
-		    set y [expr {[winfo vrooty $w] + [winfo vrootheight $w] + [winfo rooty $w] - $mh}]
-		}
-		incr x [lindex $xoffset 1]
-		incr y [lindex $yoffset 1]
-		PostOverPoint $menu $x $y
-	    }
-	    left {
-		set x [expr {[winfo rootx $w] - [winfo reqwidth $menu]}]
-		set y [expr {(2 * [winfo rooty $w] + [winfo height $w]) / 2}]
-		set entry [MenuFindName $menu [$w cget -text]]
-		if {$entry eq ""} {
-                    set entry 0
-		}
-		if {[$w cget -indicatoron]} {
-		    if {$entry == [$menu index last]} {
-			incr y [expr {-([$menu yposition $entry] \
-				+ [winfo reqheight $menu])/2}]
-		    } else {
-			incr y [expr {-([$menu yposition $entry] \
-			        + [$menu yposition [expr {$entry+1}]])/2}]
-		    }
-		}
-		incr x [lindex $xoffset 2]
-		incr y [lindex $yoffset 2]
-		PostOverPoint $menu $x $y
-		if {$entry ne "" \
-			&& [$menu entrycget $entry -state] ne "disabled"} {
-		    $menu activate $entry
-		    GenerateMenuSelect $menu
-		}
-	    }
-	    right {
-		set x [expr {[winfo rootx $w] + [winfo width $w]}]
-		set y [expr {(2 * [winfo rooty $w] + [winfo height $w]) / 2}]
-		set entry [MenuFindName $menu [$w cget -text]]
-		if {$entry eq ""} {
-                    set entry 0
-		}
-		if {[$w cget -indicatoron]} {
-		    if {$entry == [$menu index last]} {
-			incr y [expr {-([$menu yposition $entry] \
-				+ [winfo reqheight $menu])/2}]
-		    } else {
-			incr y [expr {-([$menu yposition $entry] \
-			        + [$menu yposition [expr {$entry+1}]])/2}]
-		    }
-		}
-		incr x [lindex $xoffset 3]
-		incr y [lindex $yoffset 3]
-		PostOverPoint $menu $x $y
-		if {$entry ne "" \
-			&& [$menu entrycget $entry -state] ne "disabled"} {
-		    $menu activate $entry
-		    GenerateMenuSelect $menu
-		}
-	    }
-	    default {
-		incr x [lindex $xoffset 4]
-		incr y [lindex $yoffset 4]
-		if {[$w cget -indicatoron]} {
-		    if {$y eq ""} {
-			set x [expr {[winfo rootx $w] + [winfo width $w]/2}]
-			set y [expr {[winfo rooty $w] + [winfo height $w]/2}]
-		    }
-	            PostOverPoint $menu $x $y [MenuFindName $menu [$w cget -text]]
-		} else {
-		    PostOverPoint $menu [winfo rootx $w] [expr {[winfo rooty $w]+[winfo height $w]}]
-		}
-	    }
-	}
-    } msg opt]} {
+
+    if {[catch {PostMenubuttonMenu $w $menu} msg opt]} {
 	# Error posting menu (e.g. bogus -postcommand). Unpost it and
 	# reflect the error.
-
 	MenuUnpost {}
 	return -options $opt $msg
     }
 
     set Priv(tearoff) $tearoff
-    if {$tearoff != 0} {
+    if {$tearoff != 0 && [tk windowingsystem] ne "aqua"} {
 	focus $menu
 	if {[winfo viewable $w]} {
 	    SaveGrabInfo $w
@@ -1223,10 +1125,118 @@ proc ::tk::MenuFindName {menu s} {
     return ""
 }
 
+# ::tk::PostMenubuttonMenu --
+#
+# Given a menubutton and a menu, this procedure posts the menu at the
+# appropriate location.  If the menubutton looks like an option
+# menubutton, meaning that the indicator is on and the direction is
+# neither above nor below, then the menu is posted so that the current
+# entry is vertically aligned with the menubutton.  On the Mac this
+# will expose a small amount of the blue indicator on the right hand
+# side.  On other platforms the entry is centered over the button.
+
+if {[tk windowingsystem] eq "aqua"} {
+    proc ::tk::PostMenubuttonMenu {button menu} {
+	set entry ""
+	if {[$button cget -indicatoron]} {
+	    set entry [MenuFindName $menu [$button cget -text]]
+	    if {$entry eq ""} {
+		set entry 0
+	    }
+	}
+	set x [winfo rootx $button]
+	set y [expr {2 + [winfo rooty $button]}]
+	switch [$button cget -direction] {
+	    above {
+		set entry ""
+		incr y [expr {4 - [winfo reqheight $menu]}]
+	    }
+	    below {
+		set entry ""
+		incr y [expr {2 + [winfo height $button]}]
+	    }
+	    left {
+		incr x [expr {-[winfo reqwidth $menu]}]
+	    }
+	    right {
+		incr x [winfo width $button]
+	    }
+	    default {
+		incr x [expr {[winfo width $button] - [winfo reqwidth $menu] - 5}]
+	    }
+	}
+	PostOverPoint $menu $x $y $entry
+    }
+} else {
+    proc ::tk::PostMenubuttonMenu {button menu} {
+	set entry ""
+	if {[$button cget -indicatoron]} {
+	    set entry [MenuFindName $menu [$button cget -text]]
+	    if {$entry eq ""} {
+		set entry 0
+	    }
+	}
+	if {$entry ne ""} {
+	    if {$entry == [$menu index last]} {
+		set entryHeight [expr {[winfo reqheight $menu] \
+				       - [$menu yposition $entry]}]
+	    } else {
+		set entryHeight [expr {[$menu yposition [expr {$entry+1}]] \
+					- [$menu yposition $entry]}]
+	    }
+	}
+	set x [winfo rootx $button]
+	set y [winfo rooty $button]
+	switch [$button cget -direction] {
+	    above {
+		incr y [expr {-[winfo reqheight $menu]}]
+		# if we go offscreen to the top, show as 'below'
+		if {$y < [winfo vrooty $button]} {
+		    set y [expr {[winfo vrooty $button] + [winfo rooty $button]\
+                           + [winfo reqheight $button]}]
+		}
+		set entry {}
+	    }
+	    below {
+		incr y [winfo height $button]
+		# if we go offscreen to the bottom, show as 'above'
+		set mh [winfo reqheight $menu]
+		if {($y + $mh) > ([winfo vrooty $button] + [winfo vrootheight $button])} {
+		    set y [expr {[winfo vrooty $button] + [winfo vrootheight $button] \
+			   + [winfo rooty $button] - $mh}]
+		}
+		set entry {}
+	    }
+	    left {
+		# It is not clear why this is needed.
+		if {[tk windowingsystem] eq "win32"} {
+		    incr x [expr {-4 - [winfo reqwidth $button] / 2}]
+		}
+		incr x [expr {- [winfo reqwidth $menu]}]
+	    }
+	    right {
+		incr x [expr {[winfo width $button]}]
+	    }
+	    default {
+		if {[$button cget -indicatoron]} {
+		    incr x [expr {([winfo width $button] - \
+				   [winfo reqwidth $menu])/ 2}]
+		} else {
+		    incr y [winfo height $button]
+		}
+	    }
+	}
+	PostOverPoint $menu $x $y $entry
+    }
+}
+
 # ::tk::PostOverPoint --
-# This procedure posts a given menu such that a given entry in the
-# menu is centered over a given point in the root window.  It also
-# activates the given entry.
+#
+# This procedure posts a menu on the screen so that a given entry in
+# the menu is positioned with its upper left corner at a given point
+# in the root window.  The procedure also activates that entry.  If no
+# entry is specified the upper left corner of the entire menu is
+# placed at the point.
 #
 # Arguments:
 # menu -		Menu to post.
@@ -1235,19 +1245,24 @@ proc ::tk::MenuFindName {menu s} {
 #			If omitted or specified as {}, then the menu's
 #			upper-left corner goes at (x,y).
 
-proc ::tk::PostOverPoint {menu x y {entry {}}}  {
-    if {$entry ne ""} {
-	if {$entry == [$menu index last]} {
-	    incr y [expr {-([$menu yposition $entry] \
-		    + [winfo reqheight $menu])/2}]
+if {[tk windowingsystem] ne "win32"} {
+    proc ::tk::PostOverPoint {menu x y {entry {}}}  {
+	if {$entry ne ""} {
+	    $menu post $x $y $entry
+	    if {[$menu entrycget $entry -state] ne "disabled"} {
+		$menu activate $entry
+		GenerateMenuSelect $menu
+	    }
 	} else {
-	    incr y [expr {-([$menu yposition $entry] \
-		    + [$menu yposition [expr {$entry+1}]])/2}]
+	    $menu post $x $y
 	}
-	incr x [expr {-[winfo reqwidth $menu]/2}]
+	return
     }
-
-    if {[tk windowingsystem] eq "win32"} {
+} else {
+    proc ::tk::PostOverPoint {menu x y {entry {}}}  {
+	if {$entry ne ""} {
+	    incr y [expr {-[$menu yposition $entry]}]
+	}
 	# osVersion is not available in safe interps
 	set ver 5
 	if {[info exists ::tcl_platform(osVersion)]} {
@@ -1263,7 +1278,7 @@ proc ::tk::PostOverPoint {menu x y {entry {}}}  {
 	# manager provided with Vista and Windows 7.
 	if {$ver < 6} {
 	    set yoffset [expr {[winfo screenheight $menu] \
-		    - $y - [winfo reqheight $menu] - 10}]
+				   - $y - [winfo reqheight $menu] - 10}]
 	    if {$yoffset < [winfo vrooty $menu]} {
 		# The bottom of the menu is offscreen, so adjust upwards
 		incr y [expr {$yoffset - [winfo vrooty $menu]}]
@@ -1275,11 +1290,11 @@ proc ::tk::PostOverPoint {menu x y {entry {}}}  {
 		set y [winfo vrooty $menu]
 	    }
 	}
-    }
-    $menu post $x $y
-    if {$entry ne "" && [$menu entrycget $entry -state] ne "disabled"} {
-	$menu activate $entry
-	GenerateMenuSelect $menu
+	$menu post $x $y
+	if {$entry ne "" && [$menu entrycget $entry -state] ne "disabled"} {
+	    $menu activate $entry
+	    GenerateMenuSelect $menu
+	}
     }
 }
 
diff --git a/macosx/tkMacOSXMenu.c b/macosx/tkMacOSXMenu.c
index 6315638..c7610fc 100644
--- a/macosx/tkMacOSXMenu.c
+++ b/macosx/tkMacOSXMenu.c
@@ -755,7 +755,10 @@ TkpDestroyMenuEntry(
  *
  * TkpPostMenu --
  *
- *	Posts a menu on the screen
+ *	Posts a menu on the screen.  If entry is < 0 then the menu is
+ *      drawn so its top left corner is located at the point with
+ *      screen coordinates (x, y).  Otherwise the top left corner of
+ *      the specified entry is located at that point.
  *
  * Results:
  *	None.
@@ -770,49 +773,47 @@ int
 TkpPostMenu(
     Tcl_Interp *interp,		/* The interpreter this menu lives in */
     TkMenu *menuPtr,		/* The menu we are posting */
-    int x,			/* The global x-coordinate of the top, left-
-				 * hand corner of where the menu is supposed
-				 * to be posted. */
-    int y)			/* The global y-coordinate */
+    int x, int y,		/* The screen coordinates where the top left
+				 * corner of the menu, or of the specified
+				 * entry, will be located. */
+    int entry)
 {
-
-
     /* Get the object that holds this Tk Window.*/
-    Tk_Window root;
-    root = Tk_MainWindow(interp);
+    Tk_Window root = Tk_MainWindow(interp);
+
     if (root == NULL) {
 	return TCL_ERROR;
     }
+    if (menuPtr->menuType == TEAROFF_MENU) {
+	entry -= 1;
+    }
 
     Drawable d = Tk_WindowId(root);
     NSView *rootview = TkMacOSXGetRootControl(d);
     NSWindow *win = [rootview window];
-    int result;
+    NSView *view = [win contentView];
+    NSMenu *menu = (NSMenu *) menuPtr->platformData;
+    NSMenuItem *item = nil;
+    NSInteger index = entry;
+    NSPoint location = NSMakePoint(x, tkMacOSXZeroScreenHeight - y);
+    int result, oldMode;
 
     inPostMenu = 1;
-
     result = TkPreprocessMenu(menuPtr);
     if (result != TCL_OK) {
         inPostMenu = 0;
         return result;
     }
-
-    int oldMode = Tcl_SetServiceMode(TCL_SERVICE_NONE);
-    NSView *view = [win contentView];
-    NSRect frame = NSMakeRect(x, tkMacOSXZeroScreenHeight - y, 1, 1);
-
-    frame.origin = [view convertPoint:
-	    [win tkConvertPointFromScreen:frame.origin] fromView:nil];
-
-    NSMenu *menu = (NSMenu *) menuPtr->platformData;
-    NSPopUpButtonCell *popUpButtonCell = [[NSPopUpButtonCell alloc]
-	    initTextCell:@"" pullsDown:NO];
-
-    [popUpButtonCell setAltersStateOfSelectedItem:NO];
-    [popUpButtonCell setMenu:menu];
-    [popUpButtonCell selectItem:nil];
-    [popUpButtonCell performClickWithFrame:frame inView:view];
-    [popUpButtonCell release];
+    if (index >= [menu numberOfItems]) {
+	index = [menu numberOfItems] - 1;
+    }
+    if (index >= 0) {
+	item = [menu itemAtIndex:index];
+    }
+    oldMode = Tcl_SetServiceMode(TCL_SERVICE_NONE);
+    [menu popUpMenuPositioningItem:item
+	  atLocation:[win tkConvertPointFromScreen:location]
+	  inView:view];
     Tcl_SetServiceMode(oldMode);
     inPostMenu = 0;
     return TCL_OK;
@@ -1087,6 +1088,7 @@ void
 TkpComputeStandardMenuGeometry(
     TkMenu *menuPtr)		/* Structure describing menu. */
 {
+    NSSize menuSize = [(NSMenu *)menuPtr->platformData size];
     Tk_Font tkfont, menuFont;
     Tk_FontMetrics menuMetrics, entryMetrics, *fmPtr;
     int modifierCharWidth, menuModifierCharWidth;
@@ -1130,7 +1132,7 @@ TkpComputeStandardMenuGeometry(
 	    break;
 	}
     }
-    
+
     for (i = 0; i < menuPtr->numEntries; i++) {
 	mePtr = menuPtr->entries[i];
 	if (mePtr->type == TEAROFF_ENTRY) {
@@ -1199,6 +1201,9 @@ TkpComputeStandardMenuGeometry(
 		    height = size.height;
 		}
 	    }
+	    else {
+		/* image only. */
+	    }
 	    labelWidth = width + menuItemExtraWidth;
 	    mePtr->height = height + menuItemExtraHeight;
 	    if (mePtr->type == CASCADE_ENTRY) {
@@ -1237,18 +1242,12 @@ TkpComputeStandardMenuGeometry(
 	mePtr->x = x;
 	mePtr->y = y;
 	y += menuPtr->entries[i]->height + borderWidth;
-	if (y > windowHeight) {
-	    windowHeight = y;
-	}
     }
-
-    windowWidth = x + maxIndicatorSpace + maxWidth
-	    + 2 * activeBorderWidth + borderWidth;
-    windowHeight += borderWidth;
-
+    windowWidth = menuSize.width;
     if (windowWidth <= 0) {
 	windowWidth = 1;
     }
+    windowHeight = menuSize.height;
     if (windowHeight <= 0) {
 	windowHeight = 1;
     }
diff --git a/tests/menu.test b/tests/menu.test
index 95699ff..dcc578f 100644
--- a/tests/menu.test
+++ b/tests/menu.test
@@ -1606,7 +1606,7 @@ test menu-3.47 {MenuWidgetCmd procedure, "post" option} -setup {
     .m1 post
 } -cleanup {
 	destroy .m1
-} -returnCodes error -result {wrong # args: should be ".m1 post x y"}
+} -returnCodes error -result {wrong # args: should be ".m1 post x y ?entry?"}
 test menu-3.48 {MenuWidgetCmd procedure, "post" option} -setup {
 	destroy .m1
 } -body {
diff --git a/unix/tkUnixMenu.c b/unix/tkUnixMenu.c
index 38b6c58..f701819 100644
--- a/unix/tkUnixMenu.c
+++ b/unix/tkUnixMenu.c
@@ -889,7 +889,10 @@ DrawMenuUnderline(
  *
  * TkpPostMenu --
  *
- *	Posts a menu on the screen
+ *	Posts a menu on the screen so that the top left corner of the
+ *      specified entry is located at the point (x, y) in screen coordinates.
+ *      If the entry parameter is negative, the upper left corner of the
+ *      menu itself is placed at the point.
  *
  * Results:
  *	None.
@@ -904,8 +907,14 @@ int
 TkpPostMenu(
     Tcl_Interp *interp,
     TkMenu *menuPtr,
-    int x, int y)
+    int x, int y, int entry)
 {
+    if (entry >= menuPtr->numEntries) {
+	entry = menuPtr->numEntries - 1;
+    }
+    if (entry >= 0) {
+	y -= menuPtr->entries[entry]->y;
+    }
     return TkPostTearoffMenu(interp, menuPtr, x, y);
 }
 
@@ -1721,7 +1730,6 @@ TkpComputeStandardMenuGeometry(
     }
     windowWidth = x + indicatorSpace + labelWidth + accelWidth
 	    + 2 * activeBorderWidth + borderWidth;
-
     windowHeight += borderWidth;
 
     /*
diff --git a/win/tkWinMenu.c b/win/tkWinMenu.c
index a409764..2957b0e 100644
--- a/win/tkWinMenu.c
+++ b/win/tkWinMenu.c
@@ -743,7 +743,10 @@ ReconfigureWindowsMenu(
  *
  * TkpPostMenu --
  *
- *	Posts a menu on the screen
+ *	Posts a menu on the screen so that the top left corner of the
+ *      specified entry is located at the point (x, y) in screen coordinates.
+ *      If the entry parameter is negative, the upper left corner of the
+ *      menu itself is placed at the point.
  *
  * Results:
  *	None.
@@ -758,7 +761,7 @@ int
 TkpPostMenu(
     Tcl_Interp *interp,
     TkMenu *menuPtr,
-    int x, int y)
+    int x, int y, int entry)
 {
     HMENU winMenuHdl = (HMENU) menuPtr->platformData;
     int result, flags;
@@ -770,7 +773,6 @@ TkpPostMenu(
 	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
 
     tsdPtr->inPostMenu++;
-
     CallPendingReconfigureImmediately(menuPtr);
 
     result = TkPreprocessMenu(menuPtr);
@@ -779,6 +781,13 @@ TkpPostMenu(
 	return result;
     }
 
+    if (entry >= menuPtr->numEntries) {
+	entry = menuPtr->numEntries - 1;
+    }
+    if (entry >= 0) {
+	y -= menuPtr->entries[entry]->y;
+    }
+
     /*
      * The post commands could have deleted the menu, which means
      * we are dead and should go away.
@@ -2897,7 +2906,6 @@ TkpComputeStandardMenuGeometry(
 	    GetTearoffEntryGeometry(menuPtr, menuPtr->entries[i], tkfont,
 	    	    fmPtr, &width, &height);
 	    menuPtr->entries[i]->height = height;
-
 	} else {
 	    /*
 	     * For each entry, compute the height required by that particular
@@ -2955,8 +2963,6 @@ TkpComputeStandardMenuGeometry(
     }
     windowWidth = x + indicatorSpace + labelWidth + accelWidth
 	    + 2 * activeBorderWidth + borderWidth;
-
-
     windowHeight += borderWidth;
 
     /*