Bugfix: if the highscore file is invalid, a double free happened.

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@12408 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/race/highscore_manager.cpp

@@ -87,6 +87,7 @@ void HighscoreManager::loadHighscores()
         if(!root || root->getName()!="highscores")
         {
             if(root) delete root;
+            root = NULL;
             throw std::runtime_error("No 'highscore' node found.");
         }
         
@@ -104,6 +105,7 @@ void HighscoreManager::loadHighscores()
             // calling Save() now will generate an empty file with the right format.
             saveHighscores();
             delete root;
+            root = NULL;
             return;
         }
         
@@ -136,6 +138,7 @@ void HighscoreManager::loadHighscores()
         fprintf(stderr, "\n");
         fprintf(stderr, "No old highscores will be available.\n");
     }
+    if(root)
         delete root;
 }   // loadHighscores