Removed [Flanger] COs still referenced

[daschuer]

Bug Description

There are a couple of Mapping still referencing the no longer existing [Flanger] COs. This leads to a failed assertion:

warning [Controller] ControlDoublePrivate::getControl returning NULL for ( "[Flanger]" , "lfoPeriod" )
critical [Controller] DEBUG ASSERT: "flags.testFlag(ControlFlag::NoAssertIfMissing)" in function static QSharedPointer<ControlDoublePrivate> ControlDoublePrivate::getControl(const ConfigKey&, ControlFlags, ControlObject*, bool, bool, bool, double) at ./src/control/control.cpp:203

https://github.com/search?q=repo%3Amixxxdj%2Fmixxx%20%5BFlanger%5D&type=code

reveals 37 hits.

Version

2.5.0

OS

Ubuntu Jammy

[ronso0]

Currently users get a warning when loading a mapping that uses deprecated controls.
IIRC that means xml mappings are simply ignored and functions that use eg. Flanger will throw a warning when being called (also withan ignore option).

How do you propose to resolve this?
Shall we simply remove Flanger mappings and comment out functions using Flanger?

[daschuer]

This indicates probably that the new effect unit is not usable with this controllers. So the current state having a warning is better than having a "broken" button with no warning.

Is there a 1:1 replacement available? Probably not. So we just call out for help?

[ronso0]

Is there a 1:1 replacement available?

Nope.
It might e possible to map [ChannelN] to [EffectUnitN] and the Flanger parameters to the respective effect1 paramteres ut that's a lot of work, so yes

we just call out for help

Somehow I doubt will reach enough users when we ask for help in a blog post or in the forum.
Maybe we can refine the error/warning?
Let's say it tries to lookup the nonexistant control in a 'deprecated' list and asks for help instead of just complaining?
Is that possible? Is it worth the effort?
Usually, when users encounter such warnings they either ask for help in the forums or file a bug report.
Can we filter for 'Flanger' and