Sketcher: fixes #13999

[PaddleStroke]

fixes #13999
@wwmayer I could not reproduce the crash on windows. Can you please check and feedback if this solves correctly the crash ?

[wwmayer]

No need to test it because I can tell you straightaway that it will still crash. handleContinuousMode() calls purgeHandler that destroys the handler but returns true. So, the calling instance onModeChanged() still calls toolWidgetManager.afterHandlerModeChanged() after its destruction.

[PaddleStroke]

No need to test it because I can tell you straightaway that it will still crash. handleContinuousMode() calls purgeHandler that destroys the handler but returns true. So, the calling instance onModeChanged() still calls toolWidgetManager.afterHandlerModeChanged() after its destruction.

Actually you missed that the boolean is changed in the middle :
return !finish();

I'm not sure its the best but I felt the finish function would return true if the handler is purged. And onModeChanged return true if the mode changed, ie !finish().

Do you prefer that we avoid the '!' to keep things simpler?

[wwmayer]

Actually you missed that the boolean is changed in the middle :

Oh, you're right. OK will test it and report back.

Do you mind to change the comment right to the call of !finish to move it one line above so that won't be broken into two lines?

[wwmayer]

OK, it works!

[PaddleStroke]

Do you mind to change the comment right to the call of !finish to move it one line above so that won't be broken into two lines?

Done