Subject: 26.0.90: empty tooltips with flymake

From: [email-masked] (Charles A. Roelli)
Date: Sat, 04 Nov 2017 11:23:02 +0100

M-x find-library-other-window RET autoinsert RET
M-x flymake-mode RET
M-x flymake-goto-next-error RET
C-x o

Now place the mouse over the underlined text in the window showing
buffer autoinsert.el, without selecting the window.  An empty tooltip
shows.  If you select the window and then place the mouse over the
underlined text, the tooltip text shows up.