patch 7.4.907
Problem:    Libraries for dynamically loading interfaces can only be defined
            at compile time.
Solution:   Add options to specify the dll names. (Kazuki Sakamoto,
            closes #452)
diff --git a/src/if_lua.c b/src/if_lua.c
index 167e865..bc2d6c3 100644
--- a/src/if_lua.c
+++ b/src/if_lua.c
@@ -402,7 +402,12 @@
     int
 lua_enabled(int verbose)
 {
-    return lua_link_init(DYNAMIC_LUA_DLL, verbose) == OK;
+#ifdef WIN3264
+    char *dll = DYNAMIC_LUA_DLL;
+#else
+    char *dll = *p_luadll ? (char *)p_luadll : DYNAMIC_LUA_DLL;
+#endif
+    return lua_link_init(dll, verbose) == OK;
 }
 
 #endif /* DYNAMIC_LUA */