This patch changes the NLS currency of all Euro countries to use the "EUR" as international currency and the euro-sign (iso-8859-15, character 164).
Hmm. While I'm do not doubt that some users of Wine might find this useful, Wine is supposed to do what Windows does and if Windows does something wrong Wine usually should as well.
If I'm not mistaken the .nls contains that default values. It is entirely possible to change the currency and such in the registry to specify things differently for each user.
That said I would find it unlikely that this patch would cause any serious problem. After all, as I said, the user can specify whatever currency it likes after the defaults have been set and every application is supposed to be able to handle it.
So I do not really oppose the patch. It is more the principle I'm intrested in: Under what circumstances should Wine change the behavior if Windows does something in the wrong way?