diff --git a/mozilla/layout/base/nsCSSFrameConstructor.cpp b/mozilla/layout/base/nsCSSFrameConstructor.cpp
index b2d7b8a686b..045c393e966 100644
--- a/mozilla/layout/base/nsCSSFrameConstructor.cpp
+++ b/mozilla/layout/base/nsCSSFrameConstructor.cpp
@@ -10099,7 +10099,13 @@ nsCSSFrameConstructor::ProcessRestyledFrames(nsStyleChangeList& aChangeList,
       if (hint & (nsChangeHint_RepaintFrame | nsChangeHint_SyncFrameView)) {
         ApplyRenderingChangeToTree(aPresContext, frame, nsnull, hint);
       }
+      if (hint & nsChangeHint_UpdateCursor) {
+        nsIViewManager* viewMgr = aPresContext->GetViewManager();
+        if (viewMgr)
+          viewMgr->SynthesizeMouseMove(PR_FALSE);
+      }
     }
+
 #ifdef DEBUG
     // reget from content since it may have been regenerated...
     if (content) {
diff --git a/mozilla/layout/base/nsChangeHint.h b/mozilla/layout/base/nsChangeHint.h
index 97333af62f3..ebd71f04559 100644
--- a/mozilla/layout/base/nsChangeHint.h
+++ b/mozilla/layout/base/nsChangeHint.h
@@ -45,6 +45,7 @@ enum nsChangeHint {
   nsChangeHint_RepaintFrame = 0x01,  // change was visual only (e.g., COLOR=)
   nsChangeHint_ReflowFrame = 0x02,   // change requires reflow (e.g., WIDTH=)
   nsChangeHint_SyncFrameView = 0x04, // change requires view to be updated, if there is one (e.g., clip:)
+  nsChangeHint_UpdateCursor = 0x10,  // The currently shown mouse cursor needs to be updated
   nsChangeHint_ReconstructFrame = 0x08   // change requires frame change (e.g., display:)
                                          // This subsumes all the above
   // TBD: add nsChangeHint_ForceFrameView to force frame reconstruction if the frame doesn't yet
diff --git a/mozilla/layout/style/nsStyleContext.cpp b/mozilla/layout/style/nsStyleContext.cpp
index cc501c38794..2ff0149842a 100644
--- a/mozilla/layout/style/nsStyleContext.cpp
+++ b/mozilla/layout/style/nsStyleContext.cpp
@@ -431,7 +431,8 @@ nsStyleContext::CalcStyleDifference(nsStyleContext* aOther)
   // our position in the rule node tree is also the same.
   PRBool compare = mRuleNode != aOther->mRuleNode;
 
-  nsChangeHint maxHint = NS_STYLE_HINT_FRAMECHANGE;
+  nsChangeHint maxHint = nsChangeHint(NS_STYLE_HINT_FRAMECHANGE |
+      nsChangeHint_UpdateCursor);
   
 #define DO_STRUCT_DIFFERENCE(struct_)                                         \
   PR_BEGIN_MACRO                                                              \
diff --git a/mozilla/layout/style/nsStyleStruct.cpp b/mozilla/layout/style/nsStyleStruct.cpp
index ef81f65cdfb..4b76c430bc7 100644
--- a/mozilla/layout/style/nsStyleStruct.cpp
+++ b/mozilla/layout/style/nsStyleStruct.cpp
@@ -1693,13 +1693,12 @@ nsStyleUserInterface::nsStyleUserInterface(void)
   mCursor = NS_STYLE_CURSOR_AUTO; // fix for bugzilla bug 51113
 }
 
-nsStyleUserInterface::nsStyleUserInterface(const nsStyleUserInterface& aSource) 
+nsStyleUserInterface::nsStyleUserInterface(const nsStyleUserInterface& aSource) :
+  mUserInput(aSource.mUserInput),
+  mUserModify(aSource.mUserModify),
+  mUserFocus(aSource.mUserFocus),
+  mCursor(aSource.mCursor)
 { 
-  mUserInput = aSource.mUserInput;
-  mUserModify = aSource.mUserModify;
-  mUserFocus = aSource.mUserFocus;
-  
-  mCursor = aSource.mCursor;
 }
 
 nsStyleUserInterface::~nsStyleUserInterface(void) 
@@ -1708,31 +1707,29 @@ nsStyleUserInterface::~nsStyleUserInterface(void)
 
 nsChangeHint nsStyleUserInterface::CalcDifference(const nsStyleUserInterface& aOther) const
 {
+  nsChangeHint hint = nsChangeHint(0);
   if (mCursor != aOther.mCursor)
-    return NS_STYLE_HINT_VISUAL;
+    NS_UpdateHint(hint, nsChangeHint_UpdateCursor);
 
-  if (mUserInput == aOther.mUserInput) {
-    if (mUserModify == aOther.mUserModify) {
-      // ignore mUserFocus
-      return NS_STYLE_HINT_NONE;
-    }
-    return NS_STYLE_HINT_VISUAL;
-  }
+  if (mUserModify != aOther.mUserModify)
+    NS_UpdateHint(hint, NS_STYLE_HINT_VISUAL);
   
   if ((mUserInput != aOther.mUserInput) &&
       ((NS_STYLE_USER_INPUT_NONE == mUserInput) || 
        (NS_STYLE_USER_INPUT_NONE == aOther.mUserInput))) {
-    return NS_STYLE_HINT_FRAMECHANGE;
+    NS_UpdateHint(hint, NS_STYLE_HINT_FRAMECHANGE);
   }
 
-  return NS_STYLE_HINT_VISUAL;
+  // ignore mUserFocus
+
+  return hint;
 }
 
 #ifdef DEBUG
 /* static */
 nsChangeHint nsStyleUserInterface::MaxDifference()
 {
-  return NS_STYLE_HINT_FRAMECHANGE;
+  return nsChangeHint(nsChangeHint_UpdateCursor | NS_STYLE_HINT_FRAMECHANGE);
 }
 #endif