csprd03 - xml:lang

["Yves Savourel" <yves@opentag.com>]

In section "4.3.2 XML namespace" the specification has a provision to forbid xml:lang in <file>, <group> and <unit>.

[[
xml:lang MUST NOT be set on either the <file>, <group> , or <unit> element.
]]

This was done at the last minute after clarifying the xml:space case.
It is a good example why last minute changes are rarely a good idea: one has no time to really think about them or test them.

My understanding is that adding those prohibition was done to prevent <source> and <target> to end-up with an xml:lang implicit
value different than the expected one on <source> and <target>.

First xml:lang is not prohibited in <xliff> which makes the other prohibitions moot.

Second, this PR is really necessary: The only thing needed is to ensure that the xml:lang implicit or explicit value on <source> is
the same as the one of srcLang, and on <target> is the same as trgLang.
Those two elements already have constraints pertaining to xml:lang for explicit values, they just need to be re-worded to add
implicit values as well. This would allow the tools to use xml:lang in the rest of the document as they see fit.

I recommend to do the following:

1) Remove the provision of section 4.3.2 "xml:lang MUST NOT be set on either the <file>, <group> , or <unit> element."

2) Remove the warning text in that same section "4.3.2.1 xml:lang".

2) Change the constraint in section "4.2.2.12 source" from:

[[
When a <source> element is a child of <segment> or <ignorable> and the OPTIONAL xml:lang attribute is present, its value MUST be
equal to the value of the srcLang attribute of the enclosing <xliff> element.
]]

To:

[[
When a <source> element is a child of <segment> or <ignorable> the explicit or inherited value of the OPTIONAL xml:lang attribute
MUST be equal to the value of the srcLang attribute of the enclosing <xliff> element.
]]

3) Change the constraint in section "4.2.2.13 target" from:

[[
When a <target> element is a child of <segment> or <ignorable> and the OPTIONAL xml:lang attribute is present, its value MUST be
equal to the value of the trgLang attribute of the enclosing <xliff> element.
]]

To:

[[
When a <target> element is a child of <segment> or <ignorable> the explicit or inherited value of the OPTIONAL xml:lang attribute
MUST be equal to the value of the trgLang attribute of the enclosing <xliff> element.
]]

I have also a separate issue with " When a <target>/<source> element is a child of <segment> or <ignorable>" but I'll post a
separate comment for that.


-yves