Well, it's already changed. Do you want it changed back?

No, as the consensus for our community in Cantonese Wikipedia, the $wgSitename
is "維基百科", which is set already. However, the Namespace of the Project page is
changed from "Wikipedia" into "維基百科" too if we did not specify the
$wgMetaNamespace. The links are also going to broken if the links of the page is
going broken without this changes (which the page links still using
the "Wikipedia" namespace). This is also provide the flexibility for introduction
the Chinese Conversion (the proposed of the new conversion table is still
ongoing, which provides more convience for the users from mainland China,
however, such conversion table that currently have is not fully fits both Chinese
Wikipedia and Cantonese Wikipedia, i.e. the Proposed conversion table Blocks
(Improvements of character conversion of Chinese Wikipedia _and_ having proposal
of introduction of character conversion in Cantonese Wikipedia)).

It also provide the consistency who is familar with Chinese and English Wikipedia
(both sites are currently using the "Wikipedia" namespace) which provides more
convenience for the current users.

From the statement above I've proposed have following changes in the
LocalSettings.php file:
$wgSitename = "維基百科"; (No changes)
+$wgMetaNameSpace = "Wikipedia"; (add this line to there)

thanks, and sorry for bothering you again. :)

So, *yes* you want the namespace changed back.

Yes, but _only_ the namespace [$wgMetanamespace], _not_ the $wgSitename.

If $wgMetanamespace is not defined, it will use the $wgSitename by default, so we
need to assign the new value for [$wgMetanamespace], instead of change the value
of [$wgSitename].

Is this making more sense for you? :-)

I understand, but note that that's not actually how it works on
our sites. :)

The defaults array in InitialiseSettings.php contains a default
setting per site group, then perhaps an override for each
individual wiki. If wgMetaNamespace is not set for that wiki,
it keeps the default set for its group (eg "Wikipedia" for
*wiki, "Wiktionary" for *wiktionary, etc).

Thus in the typical case where we override both, we set both in
the configuration file. By removing the wgMetaNamespace
override, we can leave it to the English default for this
extremely rare case.

as I've seen the DefaultSettings.php file for default MediaWiki installation, the
defaults of the $wgMetaNamespace is the same as $wgSitename.

/** Will be same as you set @see $wgSitename */
$wgMetaNamespace = FALSE;

After I revised the documentation at http://www.mediawiki.org/wiki/Help:%
24wgMetaNamespace , I think that the $wgMetaNamespace should set to "Wikipedia"
in Cantonese Wikipedia site. This is for:

1. Provide more convenience for type the interlink in wikitext instead inputting

the four chinese characters using IMEs;

2. Provide a consistent usage between both Chinese and English wikipedia, as this

many editors are originally in Chinese Wikipedia and/or English Wikipedia. As
this, users can continue to use the Wikipedia namespace without knowing the new
keyword, this would be more horrible if we using the different namespace if the
$wgNamespace is the same as $wgSitename (in Cantonese wikis). ;-)

1. DefaultSettings.php is irrelevant; our InitialiseSettings.php

sets a value for this variable for all wikis. Please see my
explanation of this above in comment 5.

2. I already set wgMetaNamespace to "Wikipedia" on zh_yuewiki,

this is why this bug was marked 'RESOLVED - FIXED'.

Seems cannot find the InitialiseSettings.php in the default MediaWiki
installation package. Just wondering if the different php scripts is used on
Wikimedia sites and the default MediaWiki installation package. :-)