diff --git a/mozilla/content/base/public/nsISelectionController.idl b/mozilla/content/base/public/nsISelectionController.idl
index ad32dc879da..da495c774b9 100644
--- a/mozilla/content/base/public/nsISelectionController.idl
+++ b/mozilla/content/base/public/nsISelectionController.idl
@@ -128,6 +128,14 @@ interface nsISelectionController : nsISelectionDisplay
    */
     boolean getCaretEnabled();
 
+   /**
+   * Show the caret even in selections. By default the caret is hidden unless the
+   * selection is collapsed. Use this function to show the caret even in selections.
+   * @param aVisibility PR_TRUE to show the caret in selections.  PR_FALSE to hide.
+   * @return always NS_OK
+   */
+    void setCaretVisibilityDuringSelection(in boolean visibility);
+
    /** CharacterMove will move the selection one character forward/backward in the document.
    *  this will also have the effect of collapsing the selection if the aExtend = PR_FALSE
    *  the "point" of selection that is extended is considered the "focus" point. 
diff --git a/mozilla/layout/base/nsPresShell.cpp b/mozilla/layout/base/nsPresShell.cpp
index 12d303c3a3c..a8f3516e441 100644
--- a/mozilla/layout/base/nsPresShell.cpp
+++ b/mozilla/layout/base/nsPresShell.cpp
@@ -1193,6 +1193,7 @@ public:
   NS_IMETHOD SetCaretWidth(PRInt16 aPixels);
   NS_IMETHOD SetCaretReadOnly(PRBool aReadOnly);
   NS_IMETHOD GetCaretEnabled(PRBool *aOutEnabled);
+  NS_IMETHOD SetCaretVisibilityDuringSelection(PRBool aVisibility);
 
   NS_IMETHOD SetSelectionFlags(PRInt16 aInEnable);
   NS_IMETHOD GetSelectionFlags(PRInt16 *aOutEnable);
@@ -3190,6 +3191,13 @@ NS_IMETHODIMP PresShell::GetCaretEnabled(PRBool *aOutEnabled)
   return NS_OK;
 }
 
+NS_IMETHODIMP PresShell::SetCaretVisibilityDuringSelection(PRBool aVisibility)
+{
+  if (mCaret)
+    mCaret->SetVisibilityDuringSelection(aVisibility);
+  return NS_OK;
+}
+
 NS_IMETHODIMP PresShell::SetSelectionFlags(PRInt16 aInEnable)
 {
   mSelectionFlags = aInEnable;
diff --git a/mozilla/layout/forms/nsTextControlFrame.cpp b/mozilla/layout/forms/nsTextControlFrame.cpp
index 78e6cbf3bba..3e26f958b07 100644
--- a/mozilla/layout/forms/nsTextControlFrame.cpp
+++ b/mozilla/layout/forms/nsTextControlFrame.cpp
@@ -428,6 +428,7 @@ public:
   NS_IMETHOD SetCaretWidth(PRInt16 twips);
   NS_IMETHOD SetCaretReadOnly(PRBool aReadOnly);
   NS_IMETHOD GetCaretEnabled(PRBool *_retval);
+  NS_IMETHOD SetCaretVisibilityDuringSelection(PRBool aVisibility);
   NS_IMETHOD CharacterMove(PRBool aForward, PRBool aExtend);
   NS_IMETHOD WordMove(PRBool aForward, PRBool aExtend);
   NS_IMETHOD LineMove(PRBool aForward, PRBool aExtend);
@@ -676,6 +677,27 @@ nsTextInputSelectionImpl::GetCaretEnabled(PRBool *_retval)
   return NS_ERROR_FAILURE;
 }
 
+NS_IMETHODIMP
+nsTextInputSelectionImpl::SetCaretVisibilityDuringSelection(PRBool aVisibility)
+{
+  if (!mPresShellWeak) return NS_ERROR_NOT_INITIALIZED;
+  nsresult result;
+  nsCOMPtr<nsIPresShell> shell = do_QueryReferent(mPresShellWeak, &result);
+  if (shell)
+  {
+    nsCOMPtr<nsICaret> caret;
+    if (NS_SUCCEEDED(result = shell->GetCaret(getter_AddRefs(caret))))
+    {
+      nsCOMPtr<nsISelection> domSel;
+      if (NS_SUCCEEDED(result = mFrameSelection->GetSelection(nsISelectionController::SELECTION_NORMAL, getter_AddRefs(domSel))))
+      {
+        return caret->SetVisibilityDuringSelection(aVisibility);
+      }
+    }
+
+  }
+  return NS_ERROR_FAILURE;
+}
 
 NS_IMETHODIMP
 nsTextInputSelectionImpl::CharacterMove(PRBool aForward, PRBool aExtend)
diff --git a/mozilla/layout/html/base/src/nsPresShell.cpp b/mozilla/layout/html/base/src/nsPresShell.cpp
index 12d303c3a3c..a8f3516e441 100644
--- a/mozilla/layout/html/base/src/nsPresShell.cpp
+++ b/mozilla/layout/html/base/src/nsPresShell.cpp
@@ -1193,6 +1193,7 @@ public:
   NS_IMETHOD SetCaretWidth(PRInt16 aPixels);
   NS_IMETHOD SetCaretReadOnly(PRBool aReadOnly);
   NS_IMETHOD GetCaretEnabled(PRBool *aOutEnabled);
+  NS_IMETHOD SetCaretVisibilityDuringSelection(PRBool aVisibility);
 
   NS_IMETHOD SetSelectionFlags(PRInt16 aInEnable);
   NS_IMETHOD GetSelectionFlags(PRInt16 *aOutEnable);
@@ -3190,6 +3191,13 @@ NS_IMETHODIMP PresShell::GetCaretEnabled(PRBool *aOutEnabled)
   return NS_OK;
 }
 
+NS_IMETHODIMP PresShell::SetCaretVisibilityDuringSelection(PRBool aVisibility)
+{
+  if (mCaret)
+    mCaret->SetVisibilityDuringSelection(aVisibility);
+  return NS_OK;
+}
+
 NS_IMETHODIMP PresShell::SetSelectionFlags(PRInt16 aInEnable)
 {
   mSelectionFlags = aInEnable;
diff --git a/mozilla/layout/html/forms/src/nsTextControlFrame.cpp b/mozilla/layout/html/forms/src/nsTextControlFrame.cpp
index 78e6cbf3bba..3e26f958b07 100644
--- a/mozilla/layout/html/forms/src/nsTextControlFrame.cpp
+++ b/mozilla/layout/html/forms/src/nsTextControlFrame.cpp
@@ -428,6 +428,7 @@ public:
   NS_IMETHOD SetCaretWidth(PRInt16 twips);
   NS_IMETHOD SetCaretReadOnly(PRBool aReadOnly);
   NS_IMETHOD GetCaretEnabled(PRBool *_retval);
+  NS_IMETHOD SetCaretVisibilityDuringSelection(PRBool aVisibility);
   NS_IMETHOD CharacterMove(PRBool aForward, PRBool aExtend);
   NS_IMETHOD WordMove(PRBool aForward, PRBool aExtend);
   NS_IMETHOD LineMove(PRBool aForward, PRBool aExtend);
@@ -676,6 +677,27 @@ nsTextInputSelectionImpl::GetCaretEnabled(PRBool *_retval)
   return NS_ERROR_FAILURE;
 }
 
+NS_IMETHODIMP
+nsTextInputSelectionImpl::SetCaretVisibilityDuringSelection(PRBool aVisibility)
+{
+  if (!mPresShellWeak) return NS_ERROR_NOT_INITIALIZED;
+  nsresult result;
+  nsCOMPtr<nsIPresShell> shell = do_QueryReferent(mPresShellWeak, &result);
+  if (shell)
+  {
+    nsCOMPtr<nsICaret> caret;
+    if (NS_SUCCEEDED(result = shell->GetCaret(getter_AddRefs(caret))))
+    {
+      nsCOMPtr<nsISelection> domSel;
+      if (NS_SUCCEEDED(result = mFrameSelection->GetSelection(nsISelectionController::SELECTION_NORMAL, getter_AddRefs(domSel))))
+      {
+        return caret->SetVisibilityDuringSelection(aVisibility);
+      }
+    }
+
+  }
+  return NS_ERROR_FAILURE;
+}
 
 NS_IMETHODIMP
 nsTextInputSelectionImpl::CharacterMove(PRBool aForward, PRBool aExtend)
diff --git a/mozilla/widget/src/xpwidgets/nsXPLookAndFeel.cpp b/mozilla/widget/src/xpwidgets/nsXPLookAndFeel.cpp
index 67fb370f31d..b3c54ae031c 100644
--- a/mozilla/widget/src/xpwidgets/nsXPLookAndFeel.cpp
+++ b/mozilla/widget/src/xpwidgets/nsXPLookAndFeel.cpp
@@ -85,6 +85,7 @@ nsLookAndFeelIntPref nsXPLookAndFeel::sIntPrefs[] =
     PR_FALSE, nsLookAndFeelTypeInt, 0 },
   { "ui.caretBlinkTime", eMetric_CaretBlinkTime, PR_FALSE, nsLookAndFeelTypeInt, 0 },
   { "ui.caretWidthTwips", eMetric_SingleLineCaretWidth, PR_FALSE, nsLookAndFeelTypeInt, 0 },
+  { "ui.caretVisibleWithSelection", eMetric_ShowCaretDuringSelection, PR_FALSE, nsLookAndFeelTypeInt, 0 },
   { "ui.submenuDelay", eMetric_SubmenuDelay, PR_FALSE, nsLookAndFeelTypeInt, 0 },
   { "ui.dragFullWindow", eMetric_DragFullWindow, PR_FALSE, nsLookAndFeelTypeInt, 0 },
   { "ui.dragThresholdX", eMetric_DragThresholdX, PR_FALSE, nsLookAndFeelTypeInt, 0 },