* Remove usage of label tags that are not associated with any
form elements.
* Remove setting of title for the label tags. This is not necessary
as the title text is the same as the text showed in the label.
There are inherent issues with task blocking which mean that it has
never worked properly. It is also very buggy and can lead to massive
performance issues with task processing.
It is almost impossible to deprecate this in a staged fashion because
various APIs use the methods and it is not possible to determine which
are API uses and which are other valid uses.
In reality there has been little-to-no uptake on the use of this feature
and it should just be removed.
* A presentation role is not necessary for the img tag.
- If a non-empty alt text is provided, the presentation role will
conflict with the alt text.
- An empty alt text denotes a decorative image. The presence of a
presentation role is redundant.
* Make sure that the alt text is set to an empty string. Otherwise,
an img tag without an alt attribute will be produced which is an
invalid markup.
* When text is rendered for the action icon, set the icon as a
decorative image by setting empty alt and title attributes and adding
the aria-hidden attribute as well. Otherwise, assistive technologies
will read the action name twice.
* An image with non-empty alt text should not have a presentation role.
* An empty alt attribute is sufficient for decorative images. No need to
add a presentation role for them.
* Additionally, if there is already text that is present for an image,
there's no need to add an alt text with the same text. Such images are
decorative and should just have an empty alt text.
If $CFG->enable_read_only_sessions_debug was not enabled, debugging could be
enabled part-way through a request when restart_with_write_lock was
called. This meant that a diff between the initial and final session
would be made during write_close(), although the intial session state
was never captured. This generated false positives in the logs, and it
thought any variable set in the session was a change from the original
value.
This ensures that debugging is enabled before the debug flag is allowed
to change, preventing false positives.
Also added @runInSeparateProcess on each session Redis cluster test to let the test run
in a separate process to avoid the error "the headers are not already sent" by PHPUnit.
