Update, November 28th: Dee Linden pinged me in-world to let me know the forest quest guns have now been updated with the revised script, and should work with all viewers.
On November 19th, I wrote about how recent changes in behaviour to llTakeControl meant that some users on TPVs such as Firestorm and Alchemy have found the guns used in the third of the Horizons Experience quests (Quest 3, the forest shoot-out with robots) may not work with their viewer.
At the time, the problem appeared to be due to behaviour changes made to llTakeControl as a result of SVC-7532. As these changes with this fix could “break” existing weapons in Second Life, it was not adopted by some TPVs, and so the Horizons Gun would not work with them.
However, following my article, Sue W left a comment indicating that Firestorm 4.7.9 allowed the gun to work (but not Firestorm 4.7.7 or 4.7.10). This, together with the problem as a whole, prompted further investigation on the issue by members of the Firestorm team, several of the LDPW Moles and staff from the Lab, using the Horizons staging regions.
These investigations revealed that the Horizons gun works with Firestorm 4.7.9 due to a partial fix for llTakeControl issues (quite separate to SVC-7532) which had been implemented with that release. However, as the fix had problems of its own, it was backed out for Firestorm 4.7.10 – hence why the horizons gun would not work with either 4.7.7 or 4.7.10 (except under very specific circumstances, as detailed in my previous article).
Further and extensive tests set-up by Quartz Mole, using both the Horizons Experience gun and the gun scripts used with Winter Wonderland (soon to officially reopen) revealed changes made to llTakeControl as a result of BUG-8265 were in fact responsible for the issues being experienced by some TPV users when trying to operate the Horizons gun. As a result, Quartz has re-worked the Horizons gun script, and testing shows it should now work with all viewers, and it will be deployed to the public gaming regions in the very near future.
This still leaves the issue of SVC-7532, which can still break the behaviour of older gun systems. To avoid this, Firestorm have indicated that with their upcoming release, they will introduce a toggle option, as Alchemy is doing. This will take the form of an option in Preferences which will allow users to switch between “old” and “new” llTakeControl behaviours in accordance with the weapons they are using.
With thanks to Whirly Fizzle for the update information, and Quartz Mole for extensively banging on things or the Horizons gun fix.