Added checking for modified document and prompt the user if they try to close a document without saving.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@5492 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/apps/showimage/ShowImageView.cpp

@@ -1093,6 +1093,9 @@ ShowImageView::MergeSelection()
 		
 		DeleteBitmap();
 		fBitmap = bitmap;
+		
+		BMessenger msgr(Window());
+		msgr.SendMessage(MSG_MODIFIED);
 	} else
 		delete bitmap;
 }
@@ -1469,6 +1472,9 @@ ShowImageView::AddWhiteRect(BRect &rect)
 		
 		DeleteBitmap();
 		fBitmap = bitmap;
+		
+		BMessenger msgr(Window());
+		msgr.SendMessage(MSG_MODIFIED);
 	} else
 		delete bitmap;
 }