[Development] HEADS UP: do not pass const objects to QObject::disconnect(const QMetaObject::Connection&)!

[Thiago Macieira]

On Wednesday, 8 April 2026 01:27:25 Pacific Daylight Time Volker Hilsheimer via 
Development wrote:
> Our code does not seem fundamentally different from this, which works (as it
> should) fine with gcc trunk, -O3, and -fsanitize=undefined
> 
> https://godbolt.org/z/P4fPG414s

Absence of UBSan complaint is not absence of UB. This may simply be a case not 
implemented, because the object model inside of the compiler does not carry 
enough information. And that could change at any moment, in a future compiler.

> The main argument repeated in the discussion is that this fix requires a
> recompile as well as Qt upgrade. But given that the issue evidently only
> materializes with a hypothetical future compiler, a recompile would be
> needed for that to happen anyway. So that argument seems to bite its own
> tail.

Agreed.

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Principal Engineer - Intel DCG - Platform & Sys. Eng.
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