Is there a workaround? Can these quotes be interpreted right in some way?

OK, it does seem to work with single quotes.

Can you check if " is saved as real " or as & quot ; in DB ?

You mean the end url or the question? And where to find the end url in the db?

Found it. Not very easy to find: in lime_surveys_languagesettings

https://toolsforresearch.com/report.R?code={if(!is_empty(rd),rd,"demo")} (no quotes, but &quot for ") (end url)

Ok , then seems it when saving …

Shall I mark it as done?
Before that I can add the example in the manual not to lose it if it s ok for you.

@cdorin: does marking is done mean that it is resolved now or that this is not reproducable or that it is not important enough for paying attention to?

not fixable ?

Never thought that @DenisChenu would say that something that looks so easy at this would not be fixable... Are you sure? I can hardly believe that.

1. We need to url encode simple url ( http:/example.org/&quote="&aquote=' ) (used by a lot of user)
2. But this broke specific expression (quote inside expression)
3. There are alternative (using a Equation question type for params or whole url).
4. This equation question type are more easy to test and fix

Then yes : not fixable ....

Edit
or more : make a lot of spaghetti code for a not so big benefit.

Assigned it to myself to add it into the manual