rogue4: prevent changing name or save file when using system savedir

rogue4/save.c

@@ -32,6 +32,7 @@ STAT sbuf;
  * save_game:
  *	Implement the "save game" command
  */
+/* This has to be cleaned up, these goto's are annoying. */
 save_game()
 {
     register FILE *savef;
@@ -67,6 +68,14 @@ over:
 	}
     }
 
+    if (use_savedir)
+    {
+        /* You can't change the savefile if you're using the system 
+           savedir, because that means you have privileges. */
+        msg("");
+        return FALSE;
+    }
+
     do
     {
 	mpos = 0;
@@ -102,7 +111,11 @@ gotfile:
 	}
 	strcpy(file_name, buf);
 	if ((savef = fopen(file_name, "w")) == NULL)
+        {
 	    msg(strerror(errno));	/* fake perror() */
+            if (use_savedir)
+                return FALSE;
+        }
     } while (savef == NULL);
 
     /*