bug#35961: 27.0.50; Sometimes frame freezes and stops updating (almost entirely)

[Dmitry Gutov]

The windows' contents stay almost unchanged (with the exception of some
visual glitches) in response to most commands I issue. Some weird
effects can remain, like blinking cursor(s).

It's not a Emacs freeze, because I can switch to another application and
back, and *then* the contents become updated (and still frozen
afterwards), so I can issue a command, switch back and forth and see the
result.

It happens randomly with no particular reproduction scenario. I can
never see it for a week or two, and then it happens 2-3 times a day. The
only thing in common I remember is there's usually an
*rspec-compilation* buffer shown (a third-party compilation major mode).
It often contains long lines, and while compilation is running, it
enacts a certain strain on our display engine.

What I tried:

- Evaluating

    (modify-all-frames-parameters '((inhibit-double-buffering . t)))

  => the frozen frame does not get better.

- Creating a new frame with 'C-x 5 2'. The result is a responsive frame,
  all the while the previous one is in that weird state. Further, the
  said previous frame can start updating the area of the screen where
  the new frame was initially displayed. That area doesn't change as I
  move/resize the new frame.

It's not a new problem, I've been seeing it for months on and off. It's
just weird and infrequent enough that I've held off from reporting.

In GNU Emacs 27.0.50 (build 55, x86_64-pc-linux-gnu, GTK+ Version 3.22.30)
 of 2019-05-19 built on zappa
Repository revision: 613565494d048ec758d5051484a17fdeccd42f00
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12001000
System Description: Ubuntu 18.04.2 LTS

Recent messages:
Source file ‘/home/dgutov/vc/emacs-master/lisp/filenotify.el’ newer than 
byte-compiled file
Loading autorevert (compiled; note, source file is newer)...done
Loading help-at-pt...done
Loading /home/dgutov/.custom.el (source)...done
Source file ‘/home/dgutov/vc/emacs-master/lisp/emacs-lisp/advice.el’ 
newer than byte-compiled file
Loading quail/cyrillic...done
Loading /home/dgutov/.emacs.d/site-lisp/.emacs-loaddefs.el (source)...done
Switching to window configuration: nil
Highlight tail mode enabled
For information about GNU Emacs and the GNU system, type C-h C-a.

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND GPM DBUS GSETTINGS GLIB NOTIFY INOTIFY
ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM THREADS JSON PDUMPER LCMS2 GMP

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

Major mode: Emacs-Lisp

Minor modes in effect:
  paredit-mode: t
  save-place-mode: t
  global-page-break-lines-mode: t
  page-break-lines-mode: t
  projectile-mode: t
  hes-mode: t
  global-robe-mode: t
  flymake-mode: t
  global-company-mode: t
  company-mode: t
  global-undo-tree-mode: t
  undo-tree-mode: t
  global-diff-hl-mode: t
  savehist-mode: t
  yas-global-mode: t
  yas-minor-mode: t
  global-whitespace-cleanup-mode: t
  whitespace-cleanup-mode: t
  ido-ubiquitous-mode: t
  ido-everywhere: t
  show-paren-mode: t
  electric-pair-mode: t
  delete-selection-mode: t
  cua-mode: t
  winner-mode: t
  global-auto-revert-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  auto-fill-function: yas--auto-fill
  transient-mark-mode: t

Load-path shadows:
/home/dgutov/.emacs.d/site-lisp/smartrep.el/smartrep hides 
~/.emacs.d/site-lisp/smartrep
/home/dgutov/.emacs.d/site-lisp/diff-hl/diff-hl-dired hides 
/home/dgutov/.emacs.d/elpa/diff-hl-20190223.2333/diff-hl-dired
/home/dgutov/.emacs.d/site-lisp/diff-hl/diff-hl-margin hides 
/home/dgutov/.emacs.d/elpa/diff-hl-20190223.2333/diff-hl-margin
/home/dgutov/.emacs.d/site-lisp/diff-hl/diff-hl hides 
/home/dgutov/.emacs.d/elpa/diff-hl-20190223.2333/diff-hl
/home/dgutov/.emacs.d/site-lisp/diff-hl/diff-hl-amend hides 
/home/dgutov/.emacs.d/elpa/diff-hl-20190223.2333/diff-hl-amend
/home/dgutov/.emacs.d/site-lisp/diff-hl/diff-hl-flydiff hides 
/home/dgutov/.emacs.d/elpa/diff-hl-20190223.2333/diff-hl-flydiff

Features:
(shadow sort mail-extr emacsbug smex disp-table paredit saveplace
tango-plus-theme page-break-lines smart-mode-line-light-theme
smart-mode-line rich-minority highlight-tail projectile grep ibuf-ext
ibuffer ibuffer-loaddefs highlight-escape-sequences company-oddmuse
company-keywords company-etags company-gtags company-dabbrev-code
company-dabbrev company-files company-capf company-cmake company-xcode
company-clang company-semantic company-eclim company-template
company-bbdb company-robe robe url-http url-auth url-gw nsm url
url-proxy url-privacy url-expand url-methods url-history url-cookie
url-domsuf url-util mm-view mml-smime smime dig mailcap etags fileloop
generator xref project inf-ruby ruby-end ruby-mode flymake-proc flymake
warnings thingatpt smie compile files-x company undo-tree diff diff-hl
smartrep cl face-remap vc-hg vc-git vc-dir ewoc diff-mode savehist
yasnippet-snippets yasnippet whitespace-cleanup-mode whitespace
ido-completing-read+ memoize s cus-edit wid-edit minibuf-eldef ido paren
elec-pair delsel cua-base winner .emacs-loaddefs cl-extra prelude esk
devenv commit-patch-buffer log-edit message rmc puny format-spec rfc822
mml mml-sec epa epg gnus-util rmail dframe rmail-loaddefs
text-property-search time-date mm-decode mm-bodies mm-encode mail-parse
rfc2231 mailabbrev sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils gmm-utils mailheader pcvs-util add-log vc
vc-dispatcher point-stack mmm mmm-defaults mmm-auto mmm-vars mmm-utils
mmm-compat progmodes keys find-func quail help-mode windmove hippie
hippie-exp comint derived ansi-color dired desktop frameset easy-mmode
pcase dired-loaddefs winring ring misc prefs defuns advice help-at-pt
autorevert filenotify cus-start cus-load mule-util edmacro kmacro rx
info package easymenu epg-config url-handlers url-parse auth-source
cl-seq eieio eieio-core cl-macs eieio-loaddefs password-cache json
subr-x map url-vars seq byte-opt gv bytecomp byte-compile cconv
cl-loaddefs cl-lib 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 menu-bar
rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core term/tty-colors 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 composite charscript charprop
case-table epa-hook jka-cmpr-hook help simple abbrev obarray 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 threads dbusbind
inotify lcms2 dynamic-setting system-font-setting font-render-setting
move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 420186 23205)
 (symbols 48 22245 0)
 (strings 32 70476 6962)
 (string-bytes 1 2380999)
 (vectors 16 24385)
 (vector-slots 8 311017 14478)
 (floats 8 86 88)
 (intervals 56 639 0)
 (buffers 992 12))