Patch by Psy-Fi + my minor changes

Adds conformation on exit for windows. Needs to be enabled in user perf.

Tried to edit blender.exe.manifest for more modern dialog look, but didn't work out.

intern/ghost/GHOST_C-api.h

@@ -842,6 +842,14 @@ extern void GHOST_putClipboard(GHOST_TInt8 *buffer, int selection);
  */
 extern int GHOST_toggleConsole(int action);
 
+
+/**
+ * Confirms quitting he program when there is just one window left open
+ * in the application
+ */
+extern int GHOST_confirmQuit(GHOST_WindowHandle windowhandle);
+
+
 #ifdef __cplusplus
 }
 #endif

intern/ghost/GHOST_ISystem.h

@@ -392,7 +392,11 @@ public:
 	 */
 	virtual void putClipboard(GHOST_TInt8 *buffer, bool selection) const = 0;
 
-	
+	/**
+	 * Confirms quitting he program when there is just one window left open
+	 * in the application
+	 */
+	virtual int confirmQuit(GHOST_IWindow * window) const = 0;
 protected:
 	/**
 	 * Initialize the system.

intern/ghost/intern/GHOST_C-api.cpp

@@ -865,3 +865,9 @@ int GHOST_toggleConsole(int action)
 	GHOST_ISystem* system = GHOST_ISystem::getSystem();
 	return system->toggleConsole(action);
 }
+
+
+int GHOST_confirmQuit(GHOST_WindowHandle windowhandle){
+	GHOST_ISystem* system = GHOST_ISystem::getSystem();
+	return system->confirmQuit((GHOST_IWindow*) windowhandle);
+}

intern/ghost/intern/GHOST_System.cpp

@@ -366,3 +366,9 @@ GHOST_TSuccess GHOST_System::createFullScreenWindow(GHOST_Window** window, const
 	}
 	return success;
 }
+
+
+int GHOST_System::confirmQuit(GHOST_IWindow * window) const
+{
+	return 1;
+}

intern/ghost/intern/GHOST_System.h

@@ -297,6 +297,13 @@ public:
 	   */
 	  virtual void putClipboard(GHOST_TInt8 *buffer, bool selection) const = 0;
 
+	 /**
+	 * Confirms quitting he program when there is just one window left open
+	 * in the application
+	 */
+	virtual int confirmQuit(GHOST_IWindow * window) const;
+
+
 	
 protected:
 	/**

intern/ghost/intern/GHOST_SystemWin32.cpp

@@ -1356,3 +1356,9 @@ int GHOST_SystemWin32::toggleConsole(int action)
 
 	return m_consoleStatus;
 }
+
+int GHOST_SystemWin32::confirmQuit(GHOST_IWindow * window) const
+{
+	return (MessageBox(window ? ((GHOST_WindowWin32*)window)->getHWND() : 0, "Some changes have not been saved.\nDo you really want to quit ?",
+			"Exit Blender", MB_OKCANCEL | MB_ICONWARNING | MB_TOPMOST) == IDOK);
+}

intern/ghost/intern/GHOST_SystemWin32.h

@@ -200,7 +200,13 @@ public:
 	 * @return Indication whether the event was handled. 
 	 */
 	static GHOST_TSuccess pushDragDropEvent(GHOST_TEventType eventType, GHOST_TDragnDropTypes draggedObjectType,GHOST_IWindow* window, int mouseX, int mouseY, void* data);
-	 
+	
+/**
+ * Confirms quitting he program when there is just one window left open
+ * in the application
+ */
+	virtual int confirmQuit(GHOST_IWindow * window) const;
+
 protected:
 	/**
 	 * Initializes the system.

release/scripts/startup/bl_ui/space_userpref.py

@@ -244,6 +244,9 @@ class USERPREF_PT_interface(Panel):
 
         col.prop(view, "show_splash")
 
+        if os.name == 'nt':
+            col.prop(view, "quit_dialog")
+
 
 class USERPREF_PT_edit(Panel):
     bl_space_type = 'USER_PREFERENCES'

source/blender/makesdna/DNA_userdef_types.h

@@ -510,6 +510,7 @@ extern UserDef U; /* from blenkernel blender.c */
 #define USER_SPLASH_DISABLE		(1 << 27)
 #define USER_HIDE_RECENT		(1 << 28)
 #define USER_SHOW_THUMBNAILS	(1 << 29)
+#define USER_QUIT_PROMPT		(1 << 30)
 
 /* Auto-Keying mode */
 	/* AUTOKEY_ON is a bitflag */

source/blender/makesrna/intern/rna_userdef.c

@@ -2369,6 +2369,11 @@ static void rna_def_userdef_view(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Sub Level Menu Open Delay",
 	                         "Time delay in 1/10 seconds before automatically opening sub level menus");
 
+	prop = RNA_def_property(srna, "quit_dialog", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "uiflag", USER_QUIT_PROMPT);
+	RNA_def_property_ui_text(prop, "Prompt Quit",
+	                         "Asks for confirmation when quitting through the window close button");
+
 	/* Toolbox click-hold delay */
 	prop = RNA_def_property(srna, "open_left_mouse_delay", PROP_INT, PROP_NONE);
 	RNA_def_property_int_sdna(prop, NULL, "tb_leftmouse");

source/blender/windowmanager/intern/wm_window.c

@@ -250,8 +250,25 @@ wmWindow *wm_window_copy(bContext *C, wmWindow *winorig)
 /* this is event from ghost, or exit-blender op */
 void wm_window_close(bContext *C, wmWindowManager *wm, wmWindow *win)
 {
+	wmWindow *tmpwin;
 	bScreen *screen= win->screen;
 	
+	/* first check if we have any non-temp remaining windows */
+	if((U.uiflag & USER_QUIT_PROMPT) && !wm->file_saved){
+		if(wm->windows.first) {
+			for(tmpwin = wm->windows.first; tmpwin; tmpwin = tmpwin->next){
+				if(tmpwin == win)
+					continue;
+				if(tmpwin->screen->temp == 0)
+					break;
+			}
+			if(tmpwin == NULL){
+				if(!GHOST_confirmQuit(win->ghostwin))
+					return;
+			}
+		}
+	}
+
 	BLI_remlink(&wm->windows, win);
 	
 	wm_draw_window_clear(win);