[PATCH] Fix write to uninitialized bytes for XCB event

[Enrico Forestieri]

On Wed, Feb 19, 2020 at 01:19:54PM -0500, Scott Kostyshak wrote:
> 
> It seems I committed too soon. Sorry for not waiting. Both the macro
> approach and Enrico's proposal are cleaner than my approach. I was
> planning to pursue the macro approach in a follow-up commit.

Apparently, the macro approach was abandoned by the Qt folks.

> Regarding
> C++11, don't we already use range-based for loops? Or is the question
> about if we require *all* of C++11?

The latter. As shown by Pavel in the other post gcc 4.7 is lacking
something. As we use xcb_selection_notify_event_t only in one place,
I think defining a macro is overkill. In order to avoid many calls
to calloc() (I don't know how memory fragmentation is dealt with by
modern compilers), we could anyway use that idea as follows:

	union {
		xcb_selection_notify_event_t event;
		char padding[32];
	} padded_event;
	auto & nev = padded_event.event;

-- 
Enrico