Sql2012 FOR XML Inconsistent "empty element" Behavior - sql

Question

I have an empty string in a table that I am selecting into XML. Ideally, this will produce an empty element, like <name /> instead of <name></name>.
It seems that if my empty string is the only thing I select, I get the undesired (verbose) empty tag ... but if I select other things, including another empty string (or the same empty string), I get the desirable empty tag ().
Can anyone tell me why this happens? And more importantly, how to control it?
declare #table table( TextValue nvarchar(100) )
insert into #table( TextValue ) values ( '' )
select
( select t.TextValue name for xml path( '' ), type )
from #table t
for xml path( 'row' ), root( 'root' ), type
/* result:
<root>
<row>
<name></name> <!-- select just once, verbose -->
</row>
</root>
*/
select
( select t.TextValue name for xml path( '' ), type ),
( select t.TextValue name for xml path( '' ), type )
from #table t
for xml path( 'row' ), root( 'root' ), type
/* result:
<root>
<row>
<name /> <!-- select twice, nice and neat -->
<name />
</row>
</root>
*/
Thanks!

Answer 1

It made me curious too:
That's what I came up with:
If you tell the XML engine to create XML it is done the way
open the element
fill in the content
close the element
All of these example lead to <element></element>
select '' name
for xml path( 'row' )
select '' name
,'' name2
for xml path( 'row' )
select '' name
,''
,'' name
for xml path( 'row' )
But if the XML-elment was created before the XML Engine is dealing with it, the (better) short form is used.
All of them lead to <element/>
select CAST('<name></name>' AS XML)
for xml path( 'row' )
select CAST('<name/>' AS XML)
for xml path( 'row' )
select (SELECT '' AS name FOR XML PATH(''),TYPE)
for xml path( 'row' )
UPDATE
You even can combine this
select (SELECT '' AS name FOR XML PATH(''),TYPE)
,'' AS name
for xml path( 'row' )
leads to
<row>
<name />
<name></name>
</row>
UPDATE 2
I think this has nothing to do with the element name's length. Neither is it bound to the count of columns you call. This is merely bound to: Is the XML created this moment or was it create before?
DECLARE #n1 VARCHAR(100)='';
DECLARE #n2 XML='<name></name>';
DECLARE #n3 XML='<name/>';
SELECT #n1 AS name FOR XML PATH('root');
SELECT #n2 FOR XML PATH('root');
SELECT #n3 FOR XML PATH('root');