onBufPaneOpen is called when bufpane is not fully initialized yet

[dmaluka]

Description of the problem or steps to reproduce

There is no way to find out the geometry of a newly created bufpane in onBufPaneOpen lua callback: bp:GetView() returns {0,0,0,0} instead of the actual window. The reason is that the bufpane's view is not properly initialized yet when the bufpane is created and the callback is triggered. It is initialized a bit later, at the initial resize.

In addition, bp:ID() returns 0 instead of the actual bufpane's id. The reason is that SetID is called only after onBufPaneOpen is triggered.

A quick ugly hacky fix: dmaluka@e2c6680
It postpones triggering onBufPaneOpen until after the initial resize.

Specifications

Commit hash: 95ec55f
OS: any
Terminal: any

[dmaluka]

Also, for example, w.gutterOffset is not initizalized until the initial displayBuffer() call, so e.g. bp:LocFromVisual() will not work correctly when called from onBufPaneOpen.

Maybe also many other similar pitfalls.