src/juce_appframework/gui/components/layout/juce_MultiDocumentPanel.cpp

@@ -161,6 +161,7 @@ void MultiDocumentPanel::addWindow (Component* component)
     dw->setResizable (true, false);
     dw->setContentComponent (component, false, true);
     dw->setName (component->getName());
+    dw->setBackgroundColour (component->getComponentPropertyColour (T("mdiDocumentBkg_"), false, backgroundColour));
 
     int x = 4;
     Component* const topComp = getChildComponent (getNumChildComponents() - 1);
@@ -181,6 +182,10 @@ bool MultiDocumentPanel::addDocument (Component* const component,
                                       const Colour& backgroundColour,
                                       const bool deleteWhenRemoved)
 {
+    // If you try passing a full DocumentWindow or ResizableWindow in here, you'll end up
+    // with a frame-within-a-frame! Just pass in the bare content component.
+    jassert (dynamic_cast <ResizableWindow*> (component) == 0);
+
     if (component == 0 || (maximumNumDocuments > 0 && components.size() >= maximumNumDocuments))
         return false;
 

src/juce_appframework/gui/components/layout/juce_MultiDocumentPanel.h

@@ -132,6 +132,10 @@ public:
         this will fail and return false. (If it does fail, the component passed-in will not be
         deleted, even if deleteWhenRemoved was set to true).
 
+        The MultiDocumentPanel will deal with creating a window border to go around your component,
+        so just pass in the bare content component here, no need to give it a ResizableWindow
+        or DocumentWindow.
+
         @param component            the component to add
         @param backgroundColour     the background colour to use to fill the component's
                                     window or tab

src/juce_appframework/gui/components/lookandfeel/juce_LookAndFeel.cpp

@@ -1083,7 +1083,8 @@ void LookAndFeel::drawMenuBarItem (Graphics& g,
 }
 
 //==============================================================================
-void LookAndFeel::fillTextEditorBackground (Graphics& g, int width, int height, TextEditor& textEditor)
+void LookAndFeel::fillTextEditorBackground (Graphics& g, int /*width*/, int /*height*/, 
+                                            TextEditor& textEditor)
 {
     g.fillAll (textEditor.findColour (TextEditor::backgroundColourId));
 }