diff --git a/mozilla/editor/base/nsEditor.cpp b/mozilla/editor/base/nsEditor.cpp
index 33c48222e7b..e9a5e4b5709 100644
--- a/mozilla/editor/base/nsEditor.cpp
+++ b/mozilla/editor/base/nsEditor.cpp
@@ -51,12 +51,20 @@
 #include "nsIStyleContext.h"
 #include "nsIEditActionListener.h"
 
+#include "nsICSSLoader.h"
+#include "nsICSSStyleSheet.h"
+#include "nsIHTMLContentContainer.h"
+#include "nsIStyleSet.h"
+#include "nsIDocumentObserver.h"
+
 
 #ifdef NECKO
 #include "nsIIOService.h"
 #include "nsIURL.h"
 #include "nsIServiceManager.h"
 static NS_DEFINE_CID(kIOServiceCID, NS_IOSERVICE_CID);
+#else
+#include "nsIURL.h"
 #endif // NECKO
 
 #include "nsEditorShell.h"
@@ -1332,6 +1340,117 @@ NS_IMETHODIMP nsEditor::InsertAsQuotation(const nsString& aQuotedText)
   return InsertText(aQuotedText);
 }
 
+extern "C" void
+ApplyStyleSheetToPresShellDocument(nsICSSStyleSheet* aSheet, void *aData)
+{
+  nsresult rv;
+
+  nsIPresShell *presShell = (nsIPresShell *)aData;
+
+  if (presShell) {
+    nsCOMPtr<nsIStyleSet> styleSet;
+
+    rv = presShell->GetStyleSet(getter_AddRefs(styleSet));
+
+    if (NS_SUCCEEDED(rv) && styleSet) {
+      styleSet->AppendOverrideStyleSheet(aSheet);
+
+      nsCOMPtr<nsIDocumentObserver> observer = do_QueryInterface(presShell);
+      nsCOMPtr<nsIStyleSheet> styleSheet     = do_QueryInterface(aSheet);
+      nsCOMPtr<nsIDocument> document;
+
+      rv = presShell->GetDocument(getter_AddRefs(document));
+
+      if (NS_SUCCEEDED(rv) && document && observer && styleSheet)
+        rv = observer->StyleSheetAdded(document, styleSheet);
+    }
+  }
+}
+
+NS_IMETHODIMP nsEditor::ApplyStyleSheet(const nsString& aURL)
+{
+#ifdef ENABLE_JS_EDITOR_LOG
+  nsAutoJSEditorLogLock logLock(mJSEditorLog);
+
+  if (mJSEditorLog)
+    mJSEditorLog->ApplyStyleSheet(aURL);
+#endif // ENABLE_JS_EDITOR_LOG
+
+  // XXX: Note that this is not an undo-able action yet!
+
+  nsresult rv   = NS_OK;
+  nsIURI* uaURL = 0;
+
+#ifndef NECKO
+  rv = NS_NewURL(&uaURL, aURL);
+#else
+  NS_WITH_SERVICE(nsIIOService, service, kIOServiceCID, &rv);
+  if (NS_FAILED(rv)) return rv;
+
+  nsIURI *uri = nsnull;
+  rv = service->NewURI(aURL, nsnull, &uri);
+  if (NS_FAILED(rv)) return rv;
+
+  rv = uri->QueryInterface(nsIURI::GetIID(), (void**)&uaURL);
+  NS_RELEASE(uri);
+#endif // NECKO
+
+  if (NS_SUCCEEDED(rv)) {
+    nsCOMPtr<nsIDocument> document;
+
+    rv = mPresShell->GetDocument(getter_AddRefs(document));
+
+    if (NS_SUCCEEDED(rv)) {
+      if (document) {
+        nsCOMPtr<nsIHTMLContentContainer> container = do_QueryInterface(document);
+
+        if (container) {
+          nsICSSLoader *cssLoader         = 0;
+          nsICSSStyleSheet *cssStyleSheet = 0;
+
+          rv = container->GetCSSLoader(cssLoader);
+
+          if (NS_SUCCEEDED(rv)) {
+            if (cssLoader) {
+              PRBool complete;
+
+              rv = cssLoader->LoadAgentSheet(uaURL, cssStyleSheet, complete,
+                                             ApplyStyleSheetToPresShellDocument,
+                                             mPresShell);
+
+              if (NS_SUCCEEDED(rv)) {
+                if (complete) {
+                  if (cssStyleSheet) {
+                    ApplyStyleSheetToPresShellDocument(cssStyleSheet,
+                                                       mPresShell);
+                  }
+                  else
+                    rv = NS_ERROR_NULL_POINTER;
+                }
+                    
+                //
+                // If not complete, we will be notified later
+                // with a call to AddStyleSheetToEditorDocument().
+                //
+              }
+            }
+            else
+              rv = NS_ERROR_NULL_POINTER;
+          }
+        }
+        else
+          rv = NS_ERROR_NULL_POINTER;
+      }
+      else
+        rv = NS_ERROR_NULL_POINTER;
+    }
+
+    NS_RELEASE(uaURL);
+  }
+
+  return rv;
+}
+
 NS_IMETHODIMP
 nsEditor::AddEditActionListener(nsIEditActionListener *aListener)
 {
diff --git a/mozilla/editor/base/nsEditor.h b/mozilla/editor/base/nsEditor.h
index 484460844cc..72ac3c294fd 100644
--- a/mozilla/editor/base/nsEditor.h
+++ b/mozilla/editor/base/nsEditor.h
@@ -229,6 +229,8 @@ public:
 
   NS_IMETHOD InsertAsQuotation(const nsString& aQuotedText);
 
+  NS_IMETHOD ApplyStyleSheet(const nsString& aURL);
+
   NS_IMETHOD AddEditActionListener(nsIEditActionListener *aListener);
 
   NS_IMETHOD RemoveEditActionListener(nsIEditActionListener *aListener);
diff --git a/mozilla/editor/base/nsEditorShell.cpp b/mozilla/editor/base/nsEditorShell.cpp
index c75d25953ad..f582406e5c6 100644
--- a/mozilla/editor/base/nsEditorShell.cpp
+++ b/mozilla/editor/base/nsEditorShell.cpp
@@ -90,7 +90,6 @@
 #include "nsITransferable.h"
 #include "nsISupportsArray.h"
 
-
 /* Define Class IDs */
 static NS_DEFINE_IID(kAppShellServiceCID,       NS_APPSHELL_SERVICE_CID);
 static NS_DEFINE_IID(kEditorAppCoreCID,         NS_EDITORAPPCORE_CID);
@@ -616,6 +615,35 @@ NS_IMETHODIMP nsEditorShell::SetBackgroundColor(const PRUnichar *color)
   return result;
 }
 
+NS_IMETHODIMP nsEditorShell::ApplyStyleSheet(const PRUnichar *url)
+{
+  nsresult result = NS_NOINTERFACE;
+  
+  nsAutoString  aURL(url);
+
+  switch (mEditorType)
+  {
+    case ePlainTextEditorType:
+      {
+        nsCOMPtr<nsITextEditor>  textEditor = do_QueryInterface(mEditor);
+        if (textEditor)
+          result = textEditor->ApplyStyleSheet(aURL);
+      }
+      break;
+    case eHTMLTextEditorType:
+      {
+        nsCOMPtr<nsIHTMLEditor>  htmlEditor = do_QueryInterface(mEditor);
+        if (htmlEditor)
+          result = htmlEditor->ApplyStyleSheet(aURL);
+      }
+      break;
+    default:
+      result = NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  return result;
+}
+
 NS_IMETHODIMP nsEditorShell::SetBodyAttribute(const PRUnichar *attr, const PRUnichar *value)
 {
   nsresult result = NS_NOINTERFACE;
diff --git a/mozilla/editor/base/nsEditorShell.h b/mozilla/editor/base/nsEditorShell.h
index 1d44439cad7..ff15f19d66c 100644
--- a/mozilla/editor/base/nsEditorShell.h
+++ b/mozilla/editor/base/nsEditorShell.h
@@ -161,6 +161,8 @@ class nsEditorShell :   public nsIEditorShell,
 	  NS_IMETHOD SetBodyAttribute(const PRUnichar *attr, const PRUnichar *value);
 	  NS_IMETHOD SetBackgroundColor(const PRUnichar *color);
 
+	  NS_IMETHOD ApplyStyleSheet(const PRUnichar *url);
+
 	  /* string GetLocalFileURL (in nsIDOMWindow parent, in string filterType); */
 	  NS_IMETHOD GetLocalFileURL(nsIDOMWindow *parent, const PRUnichar *filterType, PRUnichar **_retval);
 
diff --git a/mozilla/editor/base/nsHTMLEditor.cpp b/mozilla/editor/base/nsHTMLEditor.cpp
index c9db5065b00..ac64e7ac9ca 100644
--- a/mozilla/editor/base/nsHTMLEditor.cpp
+++ b/mozilla/editor/base/nsHTMLEditor.cpp
@@ -708,6 +708,12 @@ nsHTMLEditor::CopyAttributes(nsIDOMNode *aDestNode, nsIDOMNode *aSourceNode)
   return nsTextEditor::CopyAttributes(aDestNode, aSourceNode);
 }
 
+NS_IMETHODIMP
+nsHTMLEditor::ApplyStyleSheet(const nsString& aURL)
+{
+  return nsTextEditor::ApplyStyleSheet(aURL);
+}
+
 //================================================================
 // HTML Editor methods
 //
diff --git a/mozilla/editor/base/nsHTMLEditor.h b/mozilla/editor/base/nsHTMLEditor.h
index c59daa964e0..ce2267f3a98 100644
--- a/mozilla/editor/base/nsHTMLEditor.h
+++ b/mozilla/editor/base/nsHTMLEditor.h
@@ -113,6 +113,9 @@ public:
   NS_IMETHOD OutputTextToStream(nsIOutputStream* aOutputStream,nsString* aCharsetOverride, PRBool aSelectionOnly);
   NS_IMETHOD OutputHTMLToStream(nsIOutputStream* aOutputStream,nsString* aCharsetOverride, PRBool aSelectionOnly);
 
+// Miscellaneous
+  NS_IMETHOD ApplyStyleSheet(const nsString& aURL);
+
 // Logging methods
 
   NS_IMETHOD StartLogging(nsIFileSpec *aLogFile);
diff --git a/mozilla/editor/base/nsJSEditorLog.cpp b/mozilla/editor/base/nsJSEditorLog.cpp
index 0e6d7190e17..f503aa793dc 100644
--- a/mozilla/editor/base/nsJSEditorLog.cpp
+++ b/mozilla/editor/base/nsJSEditorLog.cpp
@@ -839,6 +839,18 @@ nsJSEditorLog::EndComposition(void)
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
+NS_IMETHODIMP
+nsJSEditorLog::ApplyStyleSheet(const nsString& aURL)
+{
+  Write("window.editorShell.ApplyStyleSheet(\"");
+  PrintUnicode(aURL);
+  Write("\");\n");
+
+  Flush();
+
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsJSEditorLog::StartLogging(nsIFileSpec *aLogFile)
 {
diff --git a/mozilla/editor/base/nsJSEditorLog.h b/mozilla/editor/base/nsJSEditorLog.h
index cc530c2a871..be6f0134ee4 100644
--- a/mozilla/editor/base/nsJSEditorLog.h
+++ b/mozilla/editor/base/nsJSEditorLog.h
@@ -104,6 +104,8 @@ public:
   NS_IMETHOD OutputTextToStream(nsIOutputStream* aOutputStream, nsString* aCharsetOverride, PRBool aSelectionOnly);
   NS_IMETHOD OutputHTMLToStream(nsIOutputStream* aOutputStream, nsString* aCharsetOverride, PRBool aSelectionOnly);
 
+  NS_IMETHOD ApplyStyleSheet(const nsString& aURL);
+
   NS_IMETHOD GetLocalFileURL(nsIDOMWindow* aParent, const nsString& aFilterType, nsString& aReturn);
   NS_IMETHOD SetBackgroundColor(const nsString& aColor);
   NS_IMETHOD SetBodyAttribute(const nsString& aAttr, const nsString& aValue);
diff --git a/mozilla/editor/base/nsTextEditor.cpp b/mozilla/editor/base/nsTextEditor.cpp
index 083fbbfa45c..ffe87186122 100644
--- a/mozilla/editor/base/nsTextEditor.cpp
+++ b/mozilla/editor/base/nsTextEditor.cpp
@@ -1505,6 +1505,11 @@ NS_IMETHODIMP nsTextEditor::SetBodyWrapWidth(PRInt32 aWrapColumn)
   return res;
 }  
 
+NS_IMETHODIMP nsTextEditor::ApplyStyleSheet(const nsString& aURL)
+{
+  return nsEditor::ApplyStyleSheet(aURL);
+}
+
 NS_IMETHODIMP nsTextEditor::OutputTextToString(nsString& aOutputString, PRBool aSelectionOnly)
 {
   PRBool cancel;
@@ -1705,7 +1710,6 @@ NS_IMETHODIMP nsTextEditor::OutputHTMLToStream(nsIOutputStream* aOutputStream,ns
   return encoder->EncodeToStream(aOutputStream);
 }
 
-
 nsCOMPtr<nsIDOMElement>
 nsTextEditor::FindPreElement()
 {
diff --git a/mozilla/editor/base/nsTextEditor.h b/mozilla/editor/base/nsTextEditor.h
index a8b2390e59a..15e056a2887 100644
--- a/mozilla/editor/base/nsTextEditor.h
+++ b/mozilla/editor/base/nsTextEditor.h
@@ -122,6 +122,9 @@ public:
   NS_IMETHOD GetBodyWrapWidth(PRInt32 *aWrapColumn);
   NS_IMETHOD SetBodyWrapWidth(PRInt32 aWrapColumn);
 
+// Miscellaneous
+  NS_IMETHOD ApplyStyleSheet(const nsString& aURL);
+
 // Logging methods
 
   NS_IMETHOD StartLogging(nsIFileSpec *aLogFile);
diff --git a/mozilla/editor/composer/src/nsEditorShell.cpp b/mozilla/editor/composer/src/nsEditorShell.cpp
index c75d25953ad..f582406e5c6 100644
--- a/mozilla/editor/composer/src/nsEditorShell.cpp
+++ b/mozilla/editor/composer/src/nsEditorShell.cpp
@@ -90,7 +90,6 @@
 #include "nsITransferable.h"
 #include "nsISupportsArray.h"
 
-
 /* Define Class IDs */
 static NS_DEFINE_IID(kAppShellServiceCID,       NS_APPSHELL_SERVICE_CID);
 static NS_DEFINE_IID(kEditorAppCoreCID,         NS_EDITORAPPCORE_CID);
@@ -616,6 +615,35 @@ NS_IMETHODIMP nsEditorShell::SetBackgroundColor(const PRUnichar *color)
   return result;
 }
 
+NS_IMETHODIMP nsEditorShell::ApplyStyleSheet(const PRUnichar *url)
+{
+  nsresult result = NS_NOINTERFACE;
+  
+  nsAutoString  aURL(url);
+
+  switch (mEditorType)
+  {
+    case ePlainTextEditorType:
+      {
+        nsCOMPtr<nsITextEditor>  textEditor = do_QueryInterface(mEditor);
+        if (textEditor)
+          result = textEditor->ApplyStyleSheet(aURL);
+      }
+      break;
+    case eHTMLTextEditorType:
+      {
+        nsCOMPtr<nsIHTMLEditor>  htmlEditor = do_QueryInterface(mEditor);
+        if (htmlEditor)
+          result = htmlEditor->ApplyStyleSheet(aURL);
+      }
+      break;
+    default:
+      result = NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  return result;
+}
+
 NS_IMETHODIMP nsEditorShell::SetBodyAttribute(const PRUnichar *attr, const PRUnichar *value)
 {
   nsresult result = NS_NOINTERFACE;
diff --git a/mozilla/editor/composer/src/nsEditorShell.h b/mozilla/editor/composer/src/nsEditorShell.h
index 1d44439cad7..ff15f19d66c 100644
--- a/mozilla/editor/composer/src/nsEditorShell.h
+++ b/mozilla/editor/composer/src/nsEditorShell.h
@@ -161,6 +161,8 @@ class nsEditorShell :   public nsIEditorShell,
 	  NS_IMETHOD SetBodyAttribute(const PRUnichar *attr, const PRUnichar *value);
 	  NS_IMETHOD SetBackgroundColor(const PRUnichar *color);
 
+	  NS_IMETHOD ApplyStyleSheet(const PRUnichar *url);
+
 	  /* string GetLocalFileURL (in nsIDOMWindow parent, in string filterType); */
 	  NS_IMETHOD GetLocalFileURL(nsIDOMWindow *parent, const PRUnichar *filterType, PRUnichar **_retval);
 
diff --git a/mozilla/editor/idl/nsIEditorShell.idl b/mozilla/editor/idl/nsIEditorShell.idl
index fc038d10ccf..24f92c984e3 100644
--- a/mozilla/editor/idl/nsIEditorShell.idl
+++ b/mozilla/editor/idl/nsIEditorShell.idl
@@ -107,6 +107,8 @@ interface nsIEditorShell : nsISupports
   void GetTextProperty(in wstring prop, in wstring attr, in wstring value, out wstring firstHas, out wstring anyHas, out wstring allHas);
   void SetBodyAttribute(in wstring attr, in wstring value);
   void SetBackgroundColor(in wstring color);
+
+  void ApplyStyleSheet(in wstring url);
     
   /* Utility */
   wstring GetLocalFileURL(in nsIDOMWindow parent, in wstring filterType);
diff --git a/mozilla/editor/libeditor/base/nsEditor.cpp b/mozilla/editor/libeditor/base/nsEditor.cpp
index 33c48222e7b..e9a5e4b5709 100644
--- a/mozilla/editor/libeditor/base/nsEditor.cpp
+++ b/mozilla/editor/libeditor/base/nsEditor.cpp
@@ -51,12 +51,20 @@
 #include "nsIStyleContext.h"
 #include "nsIEditActionListener.h"
 
+#include "nsICSSLoader.h"
+#include "nsICSSStyleSheet.h"
+#include "nsIHTMLContentContainer.h"
+#include "nsIStyleSet.h"
+#include "nsIDocumentObserver.h"
+
 
 #ifdef NECKO
 #include "nsIIOService.h"
 #include "nsIURL.h"
 #include "nsIServiceManager.h"
 static NS_DEFINE_CID(kIOServiceCID, NS_IOSERVICE_CID);
+#else
+#include "nsIURL.h"
 #endif // NECKO
 
 #include "nsEditorShell.h"
@@ -1332,6 +1340,117 @@ NS_IMETHODIMP nsEditor::InsertAsQuotation(const nsString& aQuotedText)
   return InsertText(aQuotedText);
 }
 
+extern "C" void
+ApplyStyleSheetToPresShellDocument(nsICSSStyleSheet* aSheet, void *aData)
+{
+  nsresult rv;
+
+  nsIPresShell *presShell = (nsIPresShell *)aData;
+
+  if (presShell) {
+    nsCOMPtr<nsIStyleSet> styleSet;
+
+    rv = presShell->GetStyleSet(getter_AddRefs(styleSet));
+
+    if (NS_SUCCEEDED(rv) && styleSet) {
+      styleSet->AppendOverrideStyleSheet(aSheet);
+
+      nsCOMPtr<nsIDocumentObserver> observer = do_QueryInterface(presShell);
+      nsCOMPtr<nsIStyleSheet> styleSheet     = do_QueryInterface(aSheet);
+      nsCOMPtr<nsIDocument> document;
+
+      rv = presShell->GetDocument(getter_AddRefs(document));
+
+      if (NS_SUCCEEDED(rv) && document && observer && styleSheet)
+        rv = observer->StyleSheetAdded(document, styleSheet);
+    }
+  }
+}
+
+NS_IMETHODIMP nsEditor::ApplyStyleSheet(const nsString& aURL)
+{
+#ifdef ENABLE_JS_EDITOR_LOG
+  nsAutoJSEditorLogLock logLock(mJSEditorLog);
+
+  if (mJSEditorLog)
+    mJSEditorLog->ApplyStyleSheet(aURL);
+#endif // ENABLE_JS_EDITOR_LOG
+
+  // XXX: Note that this is not an undo-able action yet!
+
+  nsresult rv   = NS_OK;
+  nsIURI* uaURL = 0;
+
+#ifndef NECKO
+  rv = NS_NewURL(&uaURL, aURL);
+#else
+  NS_WITH_SERVICE(nsIIOService, service, kIOServiceCID, &rv);
+  if (NS_FAILED(rv)) return rv;
+
+  nsIURI *uri = nsnull;
+  rv = service->NewURI(aURL, nsnull, &uri);
+  if (NS_FAILED(rv)) return rv;
+
+  rv = uri->QueryInterface(nsIURI::GetIID(), (void**)&uaURL);
+  NS_RELEASE(uri);
+#endif // NECKO
+
+  if (NS_SUCCEEDED(rv)) {
+    nsCOMPtr<nsIDocument> document;
+
+    rv = mPresShell->GetDocument(getter_AddRefs(document));
+
+    if (NS_SUCCEEDED(rv)) {
+      if (document) {
+        nsCOMPtr<nsIHTMLContentContainer> container = do_QueryInterface(document);
+
+        if (container) {
+          nsICSSLoader *cssLoader         = 0;
+          nsICSSStyleSheet *cssStyleSheet = 0;
+
+          rv = container->GetCSSLoader(cssLoader);
+
+          if (NS_SUCCEEDED(rv)) {
+            if (cssLoader) {
+              PRBool complete;
+
+              rv = cssLoader->LoadAgentSheet(uaURL, cssStyleSheet, complete,
+                                             ApplyStyleSheetToPresShellDocument,
+                                             mPresShell);
+
+              if (NS_SUCCEEDED(rv)) {
+                if (complete) {
+                  if (cssStyleSheet) {
+                    ApplyStyleSheetToPresShellDocument(cssStyleSheet,
+                                                       mPresShell);
+                  }
+                  else
+                    rv = NS_ERROR_NULL_POINTER;
+                }
+                    
+                //
+                // If not complete, we will be notified later
+                // with a call to AddStyleSheetToEditorDocument().
+                //
+              }
+            }
+            else
+              rv = NS_ERROR_NULL_POINTER;
+          }
+        }
+        else
+          rv = NS_ERROR_NULL_POINTER;
+      }
+      else
+        rv = NS_ERROR_NULL_POINTER;
+    }
+
+    NS_RELEASE(uaURL);
+  }
+
+  return rv;
+}
+
 NS_IMETHODIMP
 nsEditor::AddEditActionListener(nsIEditActionListener *aListener)
 {
diff --git a/mozilla/editor/libeditor/base/nsEditor.h b/mozilla/editor/libeditor/base/nsEditor.h
index 484460844cc..72ac3c294fd 100644
--- a/mozilla/editor/libeditor/base/nsEditor.h
+++ b/mozilla/editor/libeditor/base/nsEditor.h
@@ -229,6 +229,8 @@ public:
 
   NS_IMETHOD InsertAsQuotation(const nsString& aQuotedText);
 
+  NS_IMETHOD ApplyStyleSheet(const nsString& aURL);
+
   NS_IMETHOD AddEditActionListener(nsIEditActionListener *aListener);
 
   NS_IMETHOD RemoveEditActionListener(nsIEditActionListener *aListener);
diff --git a/mozilla/editor/libeditor/html/nsHTMLEditor.cpp b/mozilla/editor/libeditor/html/nsHTMLEditor.cpp
index c9db5065b00..ac64e7ac9ca 100644
--- a/mozilla/editor/libeditor/html/nsHTMLEditor.cpp
+++ b/mozilla/editor/libeditor/html/nsHTMLEditor.cpp
@@ -708,6 +708,12 @@ nsHTMLEditor::CopyAttributes(nsIDOMNode *aDestNode, nsIDOMNode *aSourceNode)
   return nsTextEditor::CopyAttributes(aDestNode, aSourceNode);
 }
 
+NS_IMETHODIMP
+nsHTMLEditor::ApplyStyleSheet(const nsString& aURL)
+{
+  return nsTextEditor::ApplyStyleSheet(aURL);
+}
+
 //================================================================
 // HTML Editor methods
 //
diff --git a/mozilla/editor/libeditor/html/nsHTMLEditor.h b/mozilla/editor/libeditor/html/nsHTMLEditor.h
index c59daa964e0..ce2267f3a98 100644
--- a/mozilla/editor/libeditor/html/nsHTMLEditor.h
+++ b/mozilla/editor/libeditor/html/nsHTMLEditor.h
@@ -113,6 +113,9 @@ public:
   NS_IMETHOD OutputTextToStream(nsIOutputStream* aOutputStream,nsString* aCharsetOverride, PRBool aSelectionOnly);
   NS_IMETHOD OutputHTMLToStream(nsIOutputStream* aOutputStream,nsString* aCharsetOverride, PRBool aSelectionOnly);
 
+// Miscellaneous
+  NS_IMETHOD ApplyStyleSheet(const nsString& aURL);
+
 // Logging methods
 
   NS_IMETHOD StartLogging(nsIFileSpec *aLogFile);
diff --git a/mozilla/editor/public/nsIEditor.h b/mozilla/editor/public/nsIEditor.h
index 17298b51b17..8c300ca1d1c 100644
--- a/mozilla/editor/public/nsIEditor.h
+++ b/mozilla/editor/public/nsIEditor.h
@@ -378,6 +378,12 @@ public:
     */
   NS_IMETHOD InsertAsQuotation(const nsString& aQuotedText)=0;
 
+  /** load and apply the style sheet, specified by aURL, to
+    * the editor's document.
+    * @param aURL  The style sheet to be loaded and applied.
+    */
+  NS_IMETHOD ApplyStyleSheet(const nsString& aURL)=0;
+
   /** add an EditActionListener to the editors list of listeners. */
   NS_IMETHOD AddEditActionListener(nsIEditActionListener *aListener)=0;
 
diff --git a/mozilla/editor/public/nsIHTMLEditor.h b/mozilla/editor/public/nsIHTMLEditor.h
index 9bd05296602..bcd8c062962 100644
--- a/mozilla/editor/public/nsIHTMLEditor.h
+++ b/mozilla/editor/public/nsIHTMLEditor.h
@@ -108,6 +108,8 @@ public:
   NS_IMETHOD OutputTextToStream(nsIOutputStream* aOutputStream, nsString* aCharsetOverride, PRBool aSelectionOnly)=0;
   NS_IMETHOD OutputHTMLToStream(nsIOutputStream* aOutputStream, nsString* aCharsetOverride, PRBool aSelectionOnly)=0;
 
+  NS_IMETHOD ApplyStyleSheet(const nsString& aURL)=0;
+
 // Miscellaneous Methods
   /** Set the background color of the selected table cell, row, columne, or table,
     * or the document background if not in a table
diff --git a/mozilla/editor/public/nsITextEditor.h b/mozilla/editor/public/nsITextEditor.h
index 3cda7ccecd1..769b9546b82 100644
--- a/mozilla/editor/public/nsITextEditor.h
+++ b/mozilla/editor/public/nsITextEditor.h
@@ -348,10 +348,16 @@ public:
     *    -1 = no wrap at all
     * 
     */
-  NS_IMETHOD GetBodyWrapWidth(PRUint32 *aWrapColumn)=0;
-  NS_IMETHOD SetBodyWrapWidth(PRUint32 aWrapColumn)=0;
+  NS_IMETHOD GetBodyWrapWidth(PRInt32 *aWrapColumn)=0;
+  NS_IMETHOD SetBodyWrapWidth(PRInt32 aWrapColumn)=0;
 
 // Miscellaneous Methods
+
+  /** Apply the style sheet, specified by aURL, to the
+    * text editor's document.
+    */
+  NS_IMETHOD ApplyStyleSheet(const nsString& aURL)=0;
+
   /*
   NS_IMETHOD CheckSpelling()=0;
   NS_IMETHOD SpellingLanguage(nsIAtom *aLanguage)=0;
diff --git a/mozilla/editor/ui/composer/content/EditorCommands.js b/mozilla/editor/ui/composer/content/EditorCommands.js
index 2b64fab25ef..bd5ed3f715a 100644
--- a/mozilla/editor/ui/composer/content/EditorCommands.js
+++ b/mozilla/editor/ui/composer/content/EditorCommands.js
@@ -436,6 +436,14 @@ function OnCreateAlignmentPopup()
   
 // --------------------------- Debug stuff ---------------------------
 
+function EditorApplyStyleSheet(url)
+{
+  if (window.editorShell)
+  {
+    window.editorShell.ApplyStyleSheet(url);
+  }
+}
+
 function EditorExecuteScript(fileSpec)
 {
   fileSpec.openStreamForReading();