bug#21348: 25.0.50; Screen scaling factor >=2 causes menus, tooltips to display in the wrong place

[Ryan Prior]

I'm on Ubuntu 14.04.3 using a Dell XPS 13, which has screen resolution
3200x1800. In order to make the menus large enough to read, the screen
is scaled at x2.

However, at that scale setting, Emacs shows tooltips and menus at an
offset a few inches down and to the right of the mouse pointer.

Using the settings panel I can change the scaling factor. If I reduce it
below 2, for example to 1.88, then Emacs displays menus and tooltips
where I would expect. At a scale setting equal to or higher than 2x, the
menus and tooltips are shifted down and to the right.



In GNU Emacs 25.0.50.3 (x86_64-unknown-linux-gnu, GTK+ Version 3.10.8)
 of 2015-08-25
Repository revision: ef4c2eac6c6e1df8f40efde52d737d911cf2dcf9
Windowing system distributor `The X.Org Foundation', version 11.0.11501000
System Description:    Ubuntu 14.04.3 LTS

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GCONF GSETTINGS
NOTIFY LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11

Important settings:
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  delete-selection-mode: t
  global-anzu-mode: t
  anzu-mode: t
  diff-auto-refine-mode: t
  global-auto-complete-mode: t
  auto-complete-mode: t
  origami-mode: t
  show-paren-mode: t
  global-hl-line-mode: t
  desktop-save-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-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

Recent messages:
Loading desktop...done
Loading hl-line...done
Loading paren...done
Making url-show-status local to  *http 127.0.0.1:60551* while let-bound!
Wrote /home/ryan/.emacs.d/.emacs.desktop.lock
Desktop: 1 frame, 5 buffers restored.
For information about GNU Emacs and the GNU system, type C-h C-a.
user-error: Beginning of history; no preceding item
user-error: End of history; no default available

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message format-spec rfc822 mml mml-sec
mm-decode mm-bodies mm-encode mailabbrev gmm-utils mailheader sendmail
mail-utils delight delsel dired-x solarized-theme solarized-definitions
markdown-mode noutline outline autorevert filenotify dired anzu flymake
compile comint ansi-color ring vc vc-dispatcher vc-git diff-mode
network-stream nsm starttls tern-auto-complete auto-complete popup tern
easy-mmode url-http tls url-auth mail-parse rfc2231 rfc2047 rfc2045
ietf-drums url-gw url url-proxy url-privacy url-expand url-methods
url-history url-cookie url-domsuf url-util url-parse auth-source cl-seq
eieio eieio-core cl-macs gnus-util mm-util help-fns mail-prsvr
password-cache url-vars mailcap edmacro kmacro origami origami-parsers
cl gv s ucs-normalize dash js advice byte-opt bytecomp byte-compile
cl-extra help-mode cconv json imenu thingatpt cc-mode cc-fonts cc-guess
cc-menus cc-cmds cc-styles cc-align cc-engine cc-vars cc-defs finder-inf
go-mode-autoloads info package easymenu epg-config paren hl-line desktop
frameset cl-loaddefs pcase cl-lib cus-start cus-load time-date mule-util
tooltip eldoc electric uniquify ediff-hook vc-hooks lisp-float-type
mwheel x-win term/common-win x-dnd tool-bar dnd fontset image regexp-opt
fringe tabulated-list newcomment elisp-mode lisp-mode prog-mode register
page menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock
font-lock syntax facemenu font-core frame 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 charscript case-table epa-hook
jka-cmpr-hook help simple abbrev minibuffer 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 dbusbind inotify dynamic-setting
system-font-setting font-render-setting move-toolbar gtk x-toolkit x
multi-tty make-network-process emacs)

Memory information:
((conses 16 345073 13391)
 (symbols 48 32645 0)
 (miscs 40 334 142)
 (strings 32 55155 9852)
 (string-bytes 1 1623474)
 (vectors 16 47253)
 (vector-slots 8 817466 5450)
 (floats 8 250 54)
 (intervals 56 393 0)
 (buffers 976 16)
 (heap 1024 29843 1634))