hacked the item-use function,

XML needs cleaning up, funpointer needs to die

src/helpers.c

@@ -13,6 +13,7 @@ without prior permission by the authors of Eressea.
 #include <platform.h>
 #include "helpers.h"
 #include "vortex.h"
+#include "alchemy.h"
 
 #include <util/attrib.h>
 #include <util/base36.h>
@@ -491,20 +492,21 @@ static int lua_equipmentcallback(const struct equipment *eq, unit * u)
 
 /** callback for an item-use function written in lua. */
 static int
-use_item_lua(struct unit *u, const struct item_type *itype, int amount,
-struct order *ord)
+use_item_lua(unit *u, const item_type *itype, int amount, struct order *ord)
 {
     lua_State *L = (lua_State *)global.vm_state;
     int result = 0;
     char fname[64];
-
-    if (itype->use) {
-        return itype->use(u, itype, amount, ord);
-    }
+    int (*callout)(unit *, const item_type *, int, struct order *);
 
     strlcpy(fname, "use_", sizeof(fname));
     strlcat(fname, itype->rtype->_name, sizeof(fname));
 
+    callout = (int(*)(unit *, const item_type *, int, struct order *))get_function(fname);
+    if (callout) {
+        return callout(u, itype, amount, ord);
+    }
+
     lua_getglobal(L, fname);
     if (lua_isfunction(L, -1)) {
         tolua_pushusertype(L, (void *)u, TOLUA_CAST "unit");
@@ -520,11 +522,18 @@ struct order *ord)
             result = (int)lua_tonumber(L, -1);
             lua_pop(L, 1);
         }
+        return result;
     }
-    else {
-        log_error("use(%s) calling '%s': not a function.\n", unitname(u), fname);
-        lua_pop(L, 1);
+    if (itype->rtype->ptype) {
+        return use_potion(u, itype, amount, ord);
+    } else {
+        log_error("no such callout: %s", fname);
     }
+    if (itype->use) {
+        return itype->use(u, itype, amount, ord);
+    }
+    log_error("use(%s) calling '%s': not a function.\n", unitname(u), fname);
+    lua_pop(L, 1);
 
     return result;
 }

src/kernel/item.c

@@ -1292,9 +1292,9 @@ void register_resources(void)
     register_item_use(use_tacticcrystal, "use_tacticcrystal");
     register_item_use(use_birthdayamulet, "use_birthdayamulet");
     register_item_use(use_warmthpotion, "usewarmthpotion");
-    register_item_use(use_bloodpotion, "usebloodpotion");
+    register_item_use(use_bloodpotion, "use_peasantblood");
     register_item_use(use_healingpotion, "usehealingpotion");
-    register_item_use(use_foolpotion, "usefoolpotion");
+    register_item_use(use_foolpotion, "use_p7");
     register_item_use(use_mistletoe, "usemistletoe");
     register_item_use(use_magicboost, "usemagicboost");
     register_item_use(use_snowball, "usesnowball");

src/kernel/xmlreader.c

@@ -805,6 +805,10 @@ static item_type *xml_readitem(xmlXPathContextPtr xpath, resource_type * rtype)
     result = xmlXPathEvalExpression(BAD_CAST "potion", xpath);
     assert(result->nodesetval->nodeNr <= 1);
     if (result->nodesetval->nodeNr != 0) {
+        if ((itype->flags & ITF_CANUSE) == 0) {
+            log_error("potion %s has no use attribute", rtype->_name);
+            itype->flags |= ITF_CANUSE;
+        }
         xpath->node = result->nodesetval->nodeTab[0];
         rtype->ptype = xml_readpotion(xpath, itype);
     }