bug#41338: Toolbar-bug in Emacs 27.0.91/Pretest

[Konrad Podczeck]

To reproduce:

(1) Start Emacs (without any customizations).

(2) Open a file which has the standard toolbar, say mouse.el

(3) Do C-x m, to open a message buffer; this buffer has a toolbar _different_ 
from the standard one.

(4) Do C-x 5 2, to get the message buffer shown in a second frame.

(5) In the first frame, make the buffer showing mouse.el active again.

(6) In that buffer, do C-s, to invoke isearch and search for some word.

(7) Using the mouse, close the frame showing mouse.el, but do so in a state 
where still isearch overlays show up.

(8) Now click with mouse-1 in the remaining frame, i.e., in that showing the 
message buffer, and the toolbar changes to the standard one.

I consider this as a bug. In case it is not platform independent, I us an 
NS-build.

Konrad