You really put a lot of effort in preparing this bug ticket.
Respect.

"the reset must really reset the value (in 2.50 it's not resetted"
That is a big issue. Wonder if the issue was introduced lately. That could have an impact on LS 2.5 studies already conducted.

I'm not so sure about reset anymore. A "no answer" option seems to be more useful.
The slider with default values are often the field of discussion, if they where really answered by the proband. Speaking of LS 3.X.

You mean a "no answer" checkbox : can not really have it if question is mandatory.

"That could have an impact on LS 2.5 studies already conducted." I don't think, it was fixed in 2.0, but slider exist since 1.80 ....

for slider_default, maybe a attribute more "Set the value"

That the slider reset won't reset value and wrong value is then saved in LS 2.5 sounds like a high impact bug to me. Or I don't get it. No impact for LTS users, but for LS 2.5 users?

Lately we had a lot of discussions around sliders, default values, reset and no answer situation.

Wouldn't a no answer radiobutton or no answer slider area be a good idea? I think the reset button can than be neglected. Is there a high usage user case for reset when you can click no-answer?

I don't unterstand your statement "Can not really have it if question is mandatory." Why? That depends on the default position, right?
Without a explicit "no answer"

If the option "Slider starts at the middle position" really shouldn't set the default value, the bar has to be not filled as well.

And the intended behavior is described as "The handle is displayed at the middle of the slider except if Slider initial value is set (this will not set the initial value)." So it is just change of handle position of an unanswered question.

The default colors don't show the bar at all. Without the handle nothing can be seen. See slider.ui.jpg for an example of a clear optical indication.

slider.ui.jpg (17,767 bytes)   

slider.ui.jpg (17,767 bytes)   

default color can be set in template, not really an issue
ANd before we have same behaviour for colo

That the slider reset won't reset value and wrong value is then saved in LS 2.5 sounds like a high impact bug to me. Seems only in JS, added some event on submit

Fix committed to master branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&id=20812

Fixed only "" not set with EM

Remove default value with , : it's 11849 bug

Fix committed to develop branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&id=21391

Version 3.0.0-beta.1 released