97527 - class selector in HTML should be case insensitive

Status: RESOLVED DUPLICATE of bug 93371

(Core :: CSS Parsing and Computation, defect)

Description

[Frank Tang]

this is filed to fix bugscape bug 5640

Here are some background information

according to CSS2 http://www.w3.org/TR/REC-CSS2/selector.html#q1
5.1 Pattern matching
...
The case-sensitivity of document language element names in selectors depends on
the document language. For example, in HTML, element names are case-insensitive,
but in XML they are case-sensitive.

also 
.....

5.8.3 Class selectors

For style sheets used with HTML, authors may use the dot (.) notation as an
alternative to the "~=" notation when matching on the "class" attribute. Thus,
for HTML, "DIV.value" and "DIV[class~=value]" have the same meaning. The
attribute value must immediately follow the ".".

Example(s):

For example, we can assign style information to all elements with
class~="pastoral" as follows:

*.pastoral { color: green }  /* all elements with class~=pastoral */

or just

.pastoral { color: green }  /* all elements with class~=pastoral */

The following assigns style only to H1 elements with class~="pastoral":

Also in http://www.w3.org/TR/html4/struct/global.html#adef-class

7.5.2 Element identifiers: the id and class attributes
Attribute definitions

...
class = cdata-list [CS]
This attribute assigns a class name or set of class names to an element. Any
number of elements may be assigned the same class name or names. Multiple class
names must be separated by white space characters.
....

...

The class attribute, on the other hand, assigns one or more class names to an
element; the element may be said to belong to these classes. A class name may be
shared by several element instances. The class attribute has several roles in HTML:

    * As a style sheet selector (when an author wishes to assign style
information to a set of elements).
    * For general purpose processing by user agents.

and 
6.1 Case information

Each attribute definition includes information about the case-sensitivity of its
values. The case information is presented with the following keys:

CS
The value is case-sensitive (i.e., user agents interpret "a" and "A" differently).

Comment 1

[Frank Tang]

It looks like if we following HTML4.01 and CSS2, then

class attribute is case-sensitive, since html4.01 label it as 
[CS]

and therefore the class selector in HTML4.01 shoudl be case sensitive because
CSS2 said
"The case-sensitivity of document language element names in selectors depends on
the document language. "

however, IE treat it case-insensitive.

Comment 2

[Frank Tang]

mark this as topembed since it block bugscape 5640 and therefore bugscape 7970,
however, I don't think we should change the current behavior since it violate
the css2 specification. 

Comment 3

[Frank Tang]

Attachment: test case

Comment 4

[Frank Tang]

try the test cases, both line are blue in IE but only the second line is blue in
n6.1 

Comment 5

[Pierre Saslawsky]

*** This bug has been marked as a duplicate of 93371 ***