[3.12] gh-135661: Fix parsing start and end tags in HTMLParser according to the HTML5 standard (GH-135930) (GH-136268)
* Whitespaces no longer accepted between `</` and the tag name.
E.g. `</ script>` does not end the script section.
* Vertical tabulation (`\v`) and non-ASCII whitespaces no longer recognized
as whitespaces. The only whitespaces are `\t\n\r\f `.
* Null character (U+0000) no longer ends the tag name.
* Attributes and slashes after the tag name in end tags are now ignored,
instead of terminating after the first `>` in quoted attribute value.
E.g. `</script/foo=">"/>`.
* Multiple slashes and whitespaces between the last attribute and closing `>`
are now ignored in both start and end tags. E.g. `<a foo=bar/ //>`.
* Multiple `=` between attribute name and value are no longer collapsed.
E.g. `<a foo==bar>` produces attribute "foo" with value "=bar".
* Whitespaces between the `=` separator and attribute name or value are no
longer ignored. E.g. `<a foo =bar>` produces two attributes "foo" and
"=bar", both with value None; `<a foo= bar>` produces two attributes:
"foo" with value "" and "bar" with value None.
* Fix data loss after unclosed script or style tag (gh-86155).
Also backport test.support.subTests() (gh-135120).
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(cherry picked from commit 0243f97cbadec8d985e63b1daec5d1cbc850cae3)
Co-authored-by: Ezio Melotti <ezio.melotti@gmail.com>
Co-authored-by: Waylan Limberg <waylan.limberg@icloud.com>
5 files changed
