# Manipulator reset bug

Bug introduced in 10.3 or earlier, fixed in 10.4.

When the + opener is opened, two things happen:

x = 0;
Manipulator[Dynamic[x, (Print[#]; x = #) &], {-10, 0}]


1. the actual manipulator value # is set to be the minimum of the range;
2. the second argument of Dynamic gets evaluated.

However, when the range is set to e.g. {-10, 10}, the behavior is correct. Manipulator had a ragged history recently, check these related threads out:

While somwe were ironed out, something more basic still lurks in Manipulator.

(Mathematica 10.3, Win 7 64)

• Comments in one of linked topics are quite on point. I really like: Manipulator[1] – Kuba Dec 2 '15 at 15:27
• Thanks @Kuba, I'm aware of that, but I wanted to show that Manipulator not just resets the value but also evaluates anything else - which is scary, as always. – István Zachar Dec 2 '15 at 15:29
• Using a range of {-10, 0.01} is interesting, too. – Karsten 7. Dec 2 '15 at 15:33
• Submitted for TechSupport. – István Zachar Dec 2 '15 at 15:38
• A gif that demonstrates the new issue for this input. – Karsten 7. May 7 '16 at 14:29