I've posted this question on stackexchange already, but so far no one can
reproduce it:

https://emacs.stackexchange.com/questions/56207/are-there-different-tooltip-mechanisms


I experience some weird behavior with tooltips:

(progn
  (let* ((start (point))
         (end (progn (insert "test") (point)))
         (ov (make-overlay start end)))
    (overlay-put ov 'help-echo
                 (propertize "xxx" 'display '(image :type jpeg :file
"~/foo.jpg"))))
  (display-buffer-other-frame (get-buffer-create "dummy")))

Evaluating this code and moving the mouse pointer over test I get a tooltip
displaying the image file foo.jpg. This is what I expected. The tooltip
appears as a box with a light yellow background color with sharp corners.

But the moment I click into any frame/window the tooltip changes. Now the
tooltip contains no image but the text xxx. Furthermore the tooltip appears
as a transparent black box with rounded corners.

What's going on here? Are their two different tooltip mechanisms with
different capabilities? Can anyone reproduce this behaviour?

If I remove the code lines creating/displaying buffer dummy I do not see
the tooltip with the image (the first one), but only the second one with
the text xxx.

Here are screenshots of the two different tooltips:
[image: t1.png]
[image: t2.png]
I've tested this on Emacs 25.2.2 and 28.0.50, by starting emacs with emacs
-Q and then evaluating the code lines above.

Best regards
Andreas

ps: Output of report-emacs-bug:

In GNU Emacs 28.0.50 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.22.30,
cairo version 1.15.10)
 of 2020-03-17 built on phoenix
Repository revision: ac9acc1864b02b92de4eb2e98db7b5b0cd03e019
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.11906000
System Description: Ubuntu 18.04.4 LTS

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Configured using:
 'configure --with-imagemagick'

Configured features:
XPM JPEG TIFF GIF PNG RSVG CAIRO IMAGEMAGICK SOUND DBUS GSETTINGS GLIB
NOTIFY INOTIFY GNUTLS LIBXML2 FREETYPE HARFBUZZ ZLIB TOOLKIT_SCROLL_BARS
GTK3 X11 XDBE XIM MODULES THREADS PDUMPER LCMS2 GMP

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs
format-spec rfc822 mml easymenu mml-sec password-cache epa derived epg
epg-config gnus-util rmail rmail-loaddefs text-property-search time-date
subr-x seq byte-opt gv bytecomp byte-compile cconv mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader cl-loaddefs
cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils
tooltip eldoc electric uniquify ediff-hook vc-hooks lisp-float-type
mwheel term/x-win x-win term/common-win x-dnd tool-bar dnd fontset image
regexp-opt fringe tabulated-list replace newcomment text-mode elisp-mode
lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow isearch
timer select scroll-bar mouse jit-lock font-lock syntax facemenu
font-core term/tty-colors frame minibuffer cl-generic cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european
ethiopic indian cyrillic chinese composite charscript charprop
case-table epa-hook jka-cmpr-hook help simple abbrev obarray
cl-preloaded nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote threads dbusbind
inotify lcms2 dynamic-setting system-font-setting font-render-setting
cairo move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 44677 6022)
 (symbols 48 6297 1)
 (strings 32 15710 937)
 (string-bytes 1 510245)
 (vectors 16 9292)
 (vector-slots 8 127740 8504)
 (floats 8 19 27)
 (intervals 56 181 0)
 (buffers 1000 11))