[libcamera-devel] [PATCH] qcam: Don't crash if camera can't be opened

[Kieran Bingham]

Hi Laurent,

On 26/04/2020 23:31, Laurent Pinchart wrote:
> If the camera specified on the command line can't be opened, the
> MainWindow constructor still proceeds to check the startStopAction_,
> which results in MainWindow::startCapture() being called and trying to
> use a null camera_ object. Fix this by returning from the constructor as
> soon as the error is detected.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
>  src/qcam/main_window.cpp | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp
> index cf39ed7aceca..ed0cad417d62 100644
> --- a/src/qcam/main_window.cpp
> +++ b/src/qcam/main_window.cpp
> @@ -70,8 +70,10 @@ MainWindow::MainWindow(CameraManager *cm, const OptionsParser::Options &options)
>  
>  	/* Open the camera and start capture. */
>  	ret = openCamera();
> -	if (ret < 0)
> +	if (ret < 0) {
>  		quit();
> +		return;
> +	}

Ah indeed, I see otherwise it would start the stream on the Checked action.

I wonder if we fail to start the first camera we shouldn't stay running
(displaying our invalid stream icon), rather than quit()ing. But that's
a separate patch, and would also require changes in
MainWindow::switchCamera().


Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

>  
>  	startStopAction_->setChecked(true);
>  }
> 

-- 
Regards
--
Kieran