bug#28724: 25.3; height of echo area when displaying tooltip

[martin rudalics <rudalics@gmx.at>]

 > It should?  Where was that done, and in response to what bug report or
 > discussion?

I confused this one with a similar issue in eldoc which apparently was
fixed for Emacs 26.  I'm used to display eldoc output in tooltips so
when with tooltip-mode off I saw that Emacs 25 and 26 behaved
differently when displaying eldoc information in the echo area, I was
sure that this was due to a tooltips related change.  Sorry.

 > I see this in tooltip-show-help-non-mode:
 >
 >        (let ((message-truncate-lines t) <<<<<<<<<<<<<<<<<<<
 >              (message-log-max nil))
 >          (message "%s" help)))
 >
 > If I remove that binding, the echo area gets resized as expected to
 > show the full tooltip.  Should we remove that binding on the emacs-26
 > branch?

Likely it's there on purpose and somebody will get annoyed if we do
that.  We could make it customizable.

martin