Factor out commodity lookup code

Signed-off-by: Stephen M. Cameron <[email protected]>

commodities.c

@@ -376,6 +376,16 @@ int add_commodity(struct commodity **c, int *ncommodities, const char *category,
 	return n - 1;
 }
 
+int lookup_commodity(struct commodity *c, int ncommodities, const char *commodity_name)
+{
+	int i;
+
+	for (i = 0; i < ncommodities; i++)
+		if (strcasecmp(commodity_name, c[i].name) == 0)
+			return i;
+	return -1;
+}
+
 const char *commodity_category(int cat)
 {
 	if (cat < 0 || cat >= ncategories)

commodities.h

@@ -50,6 +50,8 @@ float commodity_calculate_price(struct commodity *c,
 int add_commodity(struct commodity **c, int *ncommodities, const char *category, const char *name, const char *unit,
 			const char *scans_as, float base_price, float volatility, float legality, int odds);
 
+int lookup_commodity(struct commodity *c, int ncommodities, const char *commodity_name);
+
 const char *commodity_category(int cat);
 const char *commodity_category_description(int cat);
 const int ncommodity_categories(void);

snis_server.c

@@ -21403,13 +21403,11 @@ static int l_lookup_commodity(lua_State *l)
 	const char *lua_commodity_name = luaL_checkstring(l, 1);
 	int i;
 
-	for (i = 0; i < ncommodities; i++) {
-		if (strcasecmp(lua_commodity_name, commodity[i].name) == 0) {
-			lua_pushnumber(l, (float) i);
-			return 1;
-		}
-	}
-	lua_pushnil(l);
+	i = lookup_commodity(commodity, ncommodities, lua_commodity_name);
+	if (i < 0)
+		lua_pushnil(l);
+	else
+		lua_pushnumber(l, (float) i);
 	return 1;
 }