An empty container has the same effect as transparency
with the cairo renderer, but creates black with Vulkan.
To avoid this, explicitly use a transparent color node.
This fixes the css blendmode example in gtk4-demo with
the Vulkan renderer.
As Timm Baedert pointed out, the previous fix made the
menubar go on top of popovers, which is just wrong. Instead,
make gtk_window_snapshot handle all direct children of the
window, taking care to stack popovers correctly.
We were node handling coordinates correctly when dealing
with differently sized child nodes in a blendmode node.
This was showing up in the gtk4-demo css blendmode example,
for blendmodes other than normal.
GtkMenu’s own keynav code, which actually bothers to account for the
layout of items, only happens if columns > 1. So, adding items to 1
column using a reverse loop meant they were placed in the Menu’s list of
children in that order, and because we only have 1 column, Menu passes
keynav up to MenuShell, which doesn’t adjust for the items’ positions.
‘Fix’ that here by adding items in the same order they’ll have when laid
out in the Menu, so keynav does what you’d expect, not the opposite. For
that, it’s simpler just to use gtk_container_add().
Let’s presume users are using add(), attach() with a non-inverted loop,
or attach() with arguments that create 2+ columns and so GtkMenu keynav.
This is important since _push_state returns a pointer into a GArray
which could be invalidated and point to garbage after the subsequent
push_state call.
This is used for example in the source tab of gtk4-demo.
It broke because GtkScrollbar no longer is a GtkRange,
but rather has one. So we need to forward the signal.
It was selecting paned separator, which means any separator at any level
of descent within a paned, including the toplevel container in GEdit.
We need to be more specific and only select the relevant separator that
is the direct child of the paned. This is what Adwaita does.
https://bugzilla.gnome.org/show_bug.cgi?id=788573
Nulling priv->button in _unset_tree_view() is asymmetrical: we create
it via init(), not _set_tree_view(), so we shouldn’t null in the latter.
Worse, doing so manifests in criticals + a SEGV easily with basic use of
testtreecolumns, removing the TVC from a TV then trying to add it to one
Finally, the wrong null-out meant dispose() failed to unref the button,
so it leaked.
https://bugzilla.gnome.org/show_bug.cgi?id=728452https://bugzilla.gnome.org/show_bug.cgi?id=788614
