Index: main.c
==================================================================
--- main.c
+++ main.c
@@ -179,10 +179,22 @@
   sqlite3_bind_blob64(st,4,data,sz,0);
   while((e=sqlite3_step(st))==SQLITE_ROW);
   if(e!=SQLITE_DONE) fatal("SQL error (%d): %s\n",e,sqlite3_errmsg(userdb));
   sqlite3_finalize(st);
 }
+
+static void load_level_index(void) {
+  long sz;
+  int i;
+  unsigned char*data=read_lump(0,LUMP_LEVEL_IDX,&sz,0);
+  if(!data) return;
+  if(sz>65536) fatal("Too many levels\n");
+  level_index=malloc((level_nindex=sz>>1)*sizeof(Uint16));
+  if(!level_index) fatal("Allocation failed\n");
+  for(i=0;i<level_nindex;i++) level_index[i]=data[i+i]|(data[i+i+1]<<8);
+  free(data);
+}
 
 const char*load_level(int lvl) {
   // Load level by ID. Returns null pointer if successful, or an error message if it failed.
   long sz=0;
   unsigned char*buf=lvl>=0?read_lump(FIL_LEVEL,lvl,&sz,0):0;
@@ -296,10 +308,17 @@
   }
   // skip level strings for now
   if(p>end) goto bad1;
   free(buf);
   level_id=lvl;
+  level_ord=0;
+  if(level_index) {
+    for(i=0;i<level_nindex;i++) if(level_index[i]==lvl) {
+      level_ord=i+1;
+      break;
+    }
+  }
   return 0;
 bad1:
   free(buf);
   return "Corrupted level data";
 bad2:
@@ -772,10 +791,11 @@
     test_mode();
     return 0;
   }
   init_usercache();
   load_classes();
+  load_level_index();
   optionquery[1]=Q_maxObjects;
   max_objects=strtoll(xrm_get_resource(resourcedb,optionquery,optionquery,2)?:"",0,0)?:0xFFFF0000L;
   annihilate();
   if(main_options['x']) {
     fprintf(stderr,"Ready for executing SQL statements.\n");