diff --git a/ChangeLog b/ChangeLog
index 9df006be2..c512b58db 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2010-06-22 Doug Simons <doug.simons@testplant.com>
+
+	* Source/NSButton.m:
+	* Source/NSMatrix.m:
+	* Source/NSMenu.m:
+	Further change to performKeyEquivalent: methods to take Shift key
+	into account for control keys (such as Return and Tab) as well as
+	function keys, and to honor keyEquivalentModifierMask for cells in
+	a matrix that implement that method. Also, ignore key events with
+	zero length (such as the Windows key) which was previously triggering
+	actions on objects with no keyEquivalent.
+
 2010-06-22  Wolfgang Lux  <wolfgang.lux@gmail.com>
 
 	* Source/NSPopUpButtonCell.m (-initTextCell:pullsDown:, -initWithCoder:,
diff --git a/Source/NSButton.m b/Source/NSButton.m
index 3fd472bb5..034a4f5da 100644
--- a/Source/NSButton.m
+++ b/Source/NSButton.m
@@ -515,15 +515,19 @@ static id buttonCellClass = nil;
 
   if ([self isEnabled] && (mw == nil || [w worksWhenModal] || mw == w))
     {
-      NSString	*key = [self keyEquivalent];
+      NSString	*keyEquivalent = [self keyEquivalent];
 
-      if (key != nil && [key isEqual: [anEvent charactersIgnoringModifiers]])
+      if ([keyEquivalent length] > 0 && [keyEquivalent isEqualToString: [anEvent charactersIgnoringModifiers]])
         {
-          const unsigned int relevantMask =
-            NSCommandKeyMask | NSAlternateKeyMask | NSControlKeyMask;
           unsigned int	mask = [self keyEquivalentModifierMask];
-
-          if (([anEvent modifierFlags] & relevantMask) == (mask & relevantMask))
+          unsigned int modifiers = [anEvent modifierFlags];
+          unsigned int relevantModifiersMask = NSCommandKeyMask | NSAlternateKeyMask | NSControlKeyMask;
+          /* Take shift key into account only for control keys and arrow and function keys */
+          if ((modifiers & NSFunctionKeyMask)
+              || [[NSCharacterSet controlCharacterSet] characterIsMember:[keyEquivalent characterAtIndex:0]])
+            relevantModifiersMask |= NSShiftKeyMask;
+          
+          if ((modifiers & relevantModifiersMask) == (mask & relevantModifiersMask))
             {
               [self performClick: self];
               return YES;
diff --git a/Source/NSMatrix.m b/Source/NSMatrix.m
index f4f50e6c9..de7aa27cf 100644
--- a/Source/NSMatrix.m
+++ b/Source/NSMatrix.m
@@ -55,6 +55,7 @@
 #include <Foundation/NSValue.h>
 #include <Foundation/NSArray.h>
 #include <Foundation/NSAutoreleasePool.h>
+#include <Foundation/NSCharacterSet.h>
 #include <Foundation/NSException.h>
 #include <Foundation/NSKeyedArchiver.h>
 #include <Foundation/NSNotification.h>
@@ -63,8 +64,8 @@
 #include <Foundation/NSString.h>
 #include <Foundation/NSZone.h>
 
-#include "AppKit/NSActionCell.h"
 #include "AppKit/NSApplication.h"
+#include "AppKit/NSButtonCell.h"
 #include "AppKit/NSColor.h"
 #include "AppKit/NSCursor.h"
 #include "AppKit/NSEvent.h"
@@ -2580,8 +2581,18 @@ static SEL getSel;
  */
 - (BOOL) performKeyEquivalent: (NSEvent*)theEvent
 {
-  NSString	*key = [theEvent charactersIgnoringModifiers];
+  NSString	*keyEquivalent = [theEvent charactersIgnoringModifiers];
+  unsigned int modifiers = [theEvent modifierFlags];
   int		i;
+  unsigned int relevantModifiersMask = NSCommandKeyMask | NSAlternateKeyMask | NSControlKeyMask;
+  unichar key = ([keyEquivalent length] > 0 ? [keyEquivalent characterAtIndex:0] : 0);
+  /* Take shift key into account only for control keys and arrow and function keys */
+  if ((modifiers & NSFunctionKeyMask)
+      || ([keyEquivalent length] > 0 && [[NSCharacterSet controlCharacterSet] characterIsMember:[keyEquivalent characterAtIndex:0]]))
+    relevantModifiersMask |= NSShiftKeyMask;
+
+  if ([keyEquivalent length] == 0)
+    return NO; // don't respond to zero-length string (such as the Windows key)
 
   for (i = 0; i < _numRows; i++)
     {
@@ -2590,9 +2601,13 @@ static SEL getSel;
       for (j = 0; j < _numCols; j++)
 	{
 	  NSCell	*aCell = _cells[i][j];;
+    unsigned int mask = 0;
+    if ([aCell respondsToSelector:@selector(keyEquivalentModifierMask)])
+      mask = [(NSButtonCell *)aCell keyEquivalentModifierMask];
 
 	  if ([aCell isEnabled]
-	    && [[aCell keyEquivalent] isEqualToString: key])
+	    && [[aCell keyEquivalent] isEqualToString: keyEquivalent]
+      && (mask & relevantModifiersMask) == (modifiers & relevantModifiersMask))
 	    {
 	      NSCell *oldSelectedCell = _selectedCell;
 	      int     oldSelectedRow = _selectedRow; 
diff --git a/Source/NSMenu.m b/Source/NSMenu.m
index 3bf2db8cf..469c4fe4c 100644
--- a/Source/NSMenu.m
+++ b/Source/NSMenu.m
@@ -1226,10 +1226,15 @@ static BOOL menuBarVisible = YES;
   unsigned      i;
   unsigned      count = [_items count];
   NSEventType   type = [theEvent type];
-  unsigned	modifiers = [theEvent modifierFlags];
+  unsigned int modifiers = [theEvent modifierFlags];
   NSString	*keyEquivalent = [theEvent charactersIgnoringModifiers];
+  unsigned int relevantModifiersMask = NSCommandKeyMask | NSAlternateKeyMask | NSControlKeyMask;
+  /* Take shift key into account only for control keys and arrow and function keys */
+  if ((modifiers & NSFunctionKeyMask)
+      || ([keyEquivalent length] > 0 && [[NSCharacterSet controlCharacterSet] characterIsMember:[keyEquivalent characterAtIndex:0]]))
+    relevantModifiersMask |= NSShiftKeyMask;
 
-  if (type != NSKeyDown && type != NSKeyUp) 
+  if ((type != NSKeyDown && type != NSKeyUp) || [keyEquivalent length] == 0)
     return NO;
              
   for (i = 0; i < count; i++)
@@ -1239,6 +1244,7 @@ static BOOL menuBarVisible = YES;
       if ([item hasSubmenu])
         {
 	  // Recurse through submenus whether active or not.
+          // Recurse through submenus whether active or not.
           if ([[item submenu] performKeyEquivalent: theEvent])
             {
               // The event has been handled by an item in the submenu.
@@ -1247,16 +1253,10 @@ static BOOL menuBarVisible = YES;
         }
       else
         {
-          unsigned int relevantMask =
-            NSCommandKeyMask | NSAlternateKeyMask | NSControlKeyMask;
           unsigned int mask = [item keyEquivalentModifierMask];
 
-          if (modifiers & NSFunctionKeyMask)
-            {
-              relevantMask |= NSShiftKeyMask;
-            }
           if ([[item keyEquivalent] isEqualToString: keyEquivalent] 
-            && (modifiers & relevantMask) == (mask & relevantMask))
+            && (modifiers & relevantModifiersMask) == (mask & relevantModifiersMask))
             {
               if ([item isEnabled])
                 {