Unnecessary padding from toolbar classes (Gin Toolbar Support)

Turns out the space at the bottom was just the background showing where the node display wasn't long enough to cover, so nothing to worry about. I created a merge request that should remove the unneeded spacing at the top.

Having trouble duplicating this on the latest 1.0.x. Is there anything non-default about either of these themes?

I was using the default, vertical toolbar for Gin. I imagine that it would be different if you were using the horizontal toolbar for Gin it might not need this, but not sure.

Theoretically it might be possible to recode this to look for classes that start with the name of the current admin theme, but not sure how many other admin themes would follow this convention.

Certainly wouldn't hurt to leave the issue open for more feedback.

Oh forgot to mention: part of this patch also removes from the render array a "node_preview" section that in my testing was empty but still had padding, and contributed half of the observed blank space at the top. Since it didn't seem to be doing anything useful (and targetting it via CSS wasn't working for me) I decided to remove it entirely.

I realized that the extra padding was actually introduced by the Gin Toolbar module instead of the theme itself. So if you're using the theme without the module, that could account for not seeing the extra spacing.

I've update the MR to target the class exclusion based on the word 'toolbar' instead of looking for the 'gin--' pattern.

Confirmed that this is still an issue.

Also noticed that with Gin toolbar disabled the styles on the header of the new window preview are disrupted. Perhaps this could become more of a 'support Gin Toolbar' issue.

I started a new MR targeting 2.1.x. Since this is now stripping all classes containing the word 'toolbar', including e.g. Admin Toolbar related classes, maybe we should keep this issue focused on that and open any follow-up issues for Gin incompatibilities?

I don't disagree with the approach of using this issue to target Gin compatibility more broadly. On the other hand, is there ever a circumstance where having a toolbar class on the content in the preview window is likely to be useful?

With this patch applied, I still see padding at the top of the page in Gin:

The culprit seems to be an empty div for the secondary toolbar, which Gin assigns a height: