Fix bug #6451 (last part): Crash when interacting with buffer-dependent dialog with no buffer open.

- First, the comment for isBufferDependent is corrected. It seems that the actual use of this function differs from the comment. As the comment said, I decided to close all dialogs that were buffer dependent, but this didn't seem to be correct for the view source pan, the outliner, and find-and-replace.

- Second, the dialogs that are buffer dependent are now closed, but dockviews are not, except for the spellchecker pane, which really depends on an open buffer, but I can't test that. 

So, please test whether the spellchecker dockviewed window behaves as one expects.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@34291 a592a061-630c-0410-9148-cb99ea01b6c8

src/frontends/qt4/Dialog.h

@@ -159,10 +159,15 @@ public:
 	/// Enable the Controller to dispatch its data back to the LyX kernel.
 	virtual void dispatchParams() = 0;
 
+	/** \return true if the dialog should be updated when the
+	 *  buffer has changed.
+	 */
+	virtual bool isBufferDependent() const = 0;
+
 	/** \return true if the dialog should be shown only when
 	 *  a buffer is open.
 	 */
-	virtual bool isBufferDependent() const = 0;
+	virtual bool needBufferOpen() const = 0;
 
 	/** \return true if the dialog can apply data also
 	 *  for ReadOnly buffers.

src/frontends/qt4/DialogView.h

@@ -41,6 +41,7 @@ protected:
 	void applyView() {}
 	bool initialiseParams(std::string const & /*data*/) { return true; }
 	void clearParams() {}
+	bool needBufferOpen() const { return isBufferDependent(); }
 	//@}
 	/// Any dialog that overrides this method should make sure to call it.
 	void closeEvent(QCloseEvent * ev)

src/frontends/qt4/DockView.h

@@ -55,6 +55,7 @@ public:
 	//@{
 	void applyView() {}
 	bool isClosing() const { return false; }
+	bool needBufferOpen() const { return false; }
 	//@}
 };
 

src/frontends/qt4/GuiDialog.h

@@ -94,6 +94,9 @@ public:
 	 *  to close or not (no point refreshing the display for example).
 	 */
 	bool isClosing() const { return is_closing_; }
+	
+	///
+	bool needBufferOpen() const { return isBufferDependent(); }
 
 	/// Update the display of the dialog whilst it is still visible.
 	virtual void updateView();

src/frontends/qt4/GuiSpellchecker.h

@@ -55,6 +55,7 @@ private:
 	void clearParams() {}
 	void dispatchParams() {}
 	bool isBufferDependent() const { return true; }
+	bool needBufferOpen() const { return true; }
 	///}
 
 	/// check text until next misspelled/unknown word

src/frontends/qt4/GuiView.cpp

@@ -3557,7 +3557,7 @@ void GuiView::updateDialogs()
 	for(; it != end; ++it) {
 		Dialog * dialog = it->second.get();
 		if (dialog) {
-			if (dialog->isBufferDependent() && !documentBufferView())
+			if (dialog->needBufferOpen() && !documentBufferView())
 				hideDialog(fromqstr(dialog->name()), 0);
 			else if (dialog->isVisibleView())
 				dialog->checkStatus();