[PATCH v1] libcamera: controls: Fix `ControlInfoMap::count(unsigned int)`

[Paul Elder]

Hi Barnabás,

Thanks for the patch.

Quoting Barnabás Pőcze (2025-04-02 13:50:10)
> The two overloads of `find()` and `at()` have the same behaviour
> regardless of the argument type: `unsigned int` or `const ControlId *`.
> However, `count()` is not so because `count(unsigned int)` only checks
> the `ControlIdMap`, and it does not check if the given id is actually
> present in the map storing the `ControlInfo` objects.
> 
> So `count()` returns 1 for every control id that is present in the
> associated `ControlIdMap` regardless of whether there is an actual
> entry for the `ControlId` associated with the given numeric id.
> 
> Fix that by simply using `find()` to determine the return value.
> 
> Signed-off-by: Barnabás Pőcze <barnabas.pocze at ideasonboard.com>

Looks good to me.

Reviewed-by: Paul Elder <paul.elder at ideasonboard.com>

> ---
>  src/libcamera/controls.cpp | 10 +---------
>  1 file changed, 1 insertion(+), 9 deletions(-)
> 
> diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
> index 70f6f6092..98fa7583d 100644
> --- a/src/libcamera/controls.cpp
> +++ b/src/libcamera/controls.cpp
> @@ -857,15 +857,7 @@ const ControlInfoMap::mapped_type &ControlInfoMap::at(unsigned int id) const
>   */
>  ControlInfoMap::size_type ControlInfoMap::count(unsigned int id) const
>  {
> -       if (!idmap_)
> -               return 0;
> -
> -       /*
> -        * The ControlInfoMap and its idmap have a 1:1 mapping between their
> -        * entries, we can thus just count the matching entries in idmap to
> -        * avoid an additional lookup.
> -        */
> -       return idmap_->count(id);
> +       return find(id) != end();
>  }
>  
>  /**
> -- 
> 2.49.0
>