[Freeciv-Dev] (PR#18220) [Patch] Fix ai_choose_help_wonder() crash

["Marko Lindqvist" <marko.lindqvist@xxxxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=18220 >


  ai_wants_role_unit() returns NULL if city cannot yet build unit. This 
may crash ai_choose_help_wonder().
  Fix attached.


  - ML


diff -Nurd -X.diff_ignore freeciv/ai/advdomestic.c freeciv/ai/advdomestic.c
--- freeciv/ai/advdomestic.c    2006-06-30 20:33:15.671875000 +0300
+++ freeciv/ai/advdomestic.c    2006-07-01 18:03:51.671875000 +0300
@@ -118,13 +118,13 @@
       /* This sets our tech want in cases where we cannot actually build
        * the unit. */
       unit_type = ai_wants_role_unit(pplayer, pcity, F_HELP_WONDER, want);
-      if (can_build_unit(pcity, unit_type)) {
+      if (unit_type != NULL) {
         choice->want = want;
         choice->type = CT_NONMIL;
         choice->choice = unit_type->index;
       } else {
-        CITY_LOG(LOG_DEBUG, pcity, "would but could not build %s, bumped reqs",
-                 unit_name(unit_type));
+        CITY_LOG(LOG_DEBUG, pcity,
+                 "would but could not build F_HELP_WONDER unit, bumped reqs");
       }
     }
   }