# Links in spoilers aren't hidden

An answer today caught my attention: https://math.stackexchange.com/a/2185406/62967

Here's an image of what I see with Safari 10.0.3 (with Firefox 52.0 it's the same):

The link in the spoiler is not hidden. Here's the picture taken with the pointer hovering over the spoiler

Here's the relevant part of the source:

Can you explicitly write up the congruences?

[1]: https://en.wikipedia.org/wiki/Monogenic_semigroup


A spoiler with a link follows. Can you see it?

• Possibly related – Daniel Fischer Mar 13 '17 at 22:02
• @DanielFischer Well, one can avoid using \color, but links are not under user's control. Anyway this is not related to MathJax. Not a big deal, but a bit annoying. – egreg Mar 13 '17 at 22:05
• Yes. I'm just saying it might be the same (or a related) mechanism causing both. – Daniel Fischer Mar 13 '17 at 22:09
• This seems to be specific to this site, and I think is a genuine bug that is something to be fixed. It does not happen on Mathematics Educators (precisely its meta), while it does happen also on meta here. Further there is a Meta Stack Exchange post about visited links showing through spoilers, which was declared fixed meta.stackexchange.com/questions/256941/… – quid Mar 13 '17 at 23:18
• @quid Thanks for the investigation; I left a comment to the meta.stackexchange answer. That question seems to address a different problem related to visited links. I did not visit the link in this spoiler. – egreg Mar 13 '17 at 23:23
• Yes. What I meant to convey with the meta.se link is to say that this type of problem seems to be something that gets fixed (as it did get fixed even in the more restrained scenario of an already visited link). While the MJ color thing got declared as 'by design'. – quid Mar 13 '17 at 23:26
• It seems the problem went away! At least for me. See the answer here and on main. – quid Mar 13 '17 at 23:54
• @quid I added a spoiler with an unvisited link (invalid, actually). It shows on my machine. A visited one is hidden, instead. – egreg Mar 14 '17 at 0:12
• Thank you for tracking this down. It is actually the same here. I was mislead byvisiting the link, then doing something else, and then noticing the link being properly hidden and not making that connection. The info that it does not happen on MESE seems correct though. I double checked and a spoiler there hides visited and unvisited alike. – quid Mar 14 '17 at 0:44
• I see the same visible unvisited link in hidden text with Google Chrome 57. – hardmath Mar 14 '17 at 1:26
• One of my most upvoted comments is about a floating link inside of a spoiler box. (Found with this SEDE query) – pjs36 Mar 14 '17 at 2:25

• Thanks, I'll mark it as accepted when the links will disappear. ;-) – egreg Mar 14 '17 at 13:05