bug#35434: [<8; 36; 7m26.2; terminal emacs: continuation line indicator missing when word wrapping is enabled

[Luis Gerhorst]

1. Start Emacs using 'emacs -Q --no-window-system'.

2. Reduce the window width until the lines in the scratch buffer wrap
around. Notice that Emacs shows a '\' at the end of each wrapped line.

3. Type M-x toggle-word-wrap. Emacs no longer shows a '\' to indicate
continuation lines. There is no way to tell whether the line contains a
newline, or whether it has been wrapped.

Notice that if you do the same in graphical Emacs (i.e. start with
'emacs -Q'), the fringes do show an indicator for continuation lines,
even with word wrapping enabled.

This is no critical bug, however, the behavior is inconsistent and not
user friendly. The following post shows, that it has also confused other
users who noticed the inconsistency:

https://stackoverflow.com/questions/12989072/showing-continuation-lines-in-emacs-in-a-text-terminal

If you think, this should not be a bug report and can point me to a
better place to discuss the issue, I will be happy to do so.

Best regards,
Luis


In GNU Emacs 26.2 (build 1, x86_64-apple-darwin18.5.0)
 of 2019-04-13 built on Mojave-2.local
Recent messages:
Package html2text is obsolete!
[mu4e] Started mu4e with 42141 messages in store
Mark saved where search started
Quit
Mark set

Process clipboard-copy finished
Mark saved where search started
Ag finished
Mark saved where search started
Quit
Configured using:
 'configure --disable-dependency-tracking --disable-silent-rules
 --enable-locallisppath=/usr/local/share/emacs/site-lisp
 --infodir=/usr/local/Cellar/emacs/26.2/share/info/emacs
 --prefix=/usr/local/Cellar/emacs/26.2 --with-gnutls --without-x
 --with-xml2 --without-dbus --with-modules --without-ns
 --without-imagemagick'

Configured features:
NOTIFY ACL GNUTLS LIBXML2 ZLIB MODULES THREADS

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

Major mode: Texinfo/P

Minor modes in effect:
  diff-auto-refine-mode: t
  TeX-PDF-mode: t
  ws-butler-mode: t
  show-paren-mode: t
  global-company-mode: t
  company-mode: t
  which-key-mode: t
  flx-ido-mode: t
  ido-vertical-mode: t
  crm-custom-mode: t
  ido-ubiquitous-mode: t
  ido-everywhere: t
  projectile-mode: t
  shell-dirtrack-mode: t
  recentf-mode: t
  global-auto-revert-mode: t
  xterm-mouse-mode: t
  override-global-mode: t
  cl-old-struct-compat-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-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
  transient-mark-mode: t

Load-path shadows:
/Users/luis/.emacs.d/site-lisp/solarized-emacs/solarized-theme-utils hides 
/Users/luis/.emacs.d/elpa/solarized-theme-1.2.2/solarized-theme-utils
/Users/luis/.emacs.d/site-lisp/solarized-emacs/solarized-dark-theme hides 
/Users/luis/.emacs.d/elpa/solarized-theme-1.2.2/solarized-dark-theme
/Users/luis/.emacs.d/site-lisp/solarized-emacs/solarized-theme hides 
/Users/luis/.emacs.d/elpa/solarized-theme-1.2.2/solarized-theme
/Users/luis/.emacs.d/site-lisp/solarized-emacs/solarized-theme-pkg hides 
/Users/luis/.emacs.d/elpa/solarized-theme-1.2.2/solarized-theme-pkg
/Users/luis/.emacs.d/site-lisp/solarized-emacs/solarized-light-theme hides 
/Users/luis/.emacs.d/elpa/solarized-theme-1.2.2/solarized-light-theme
/Users/luis/.emacs.d/site-lisp/solarized-emacs/solarized hides 
/Users/luis/.emacs.d/elpa/solarized-theme-1.2.2/solarized

Features:
(shadow face-remap emacsbug ace-window avy ag vc-svn find-dired smex
luis-mail-fastmail mu4e desktop frameset mu4e-speedbar speedbar sb-image
ezimage dframe mu4e-main mu4e-view cal-menu calendar cal-loaddefs
browse-url mu4e-headers mu4e-compose mu4e-context mu4e-draft
mu4e-actions rfc2368 smtpmail sendmail mu4e-mark mu4e-message flow-fill
html2text mu4e-proc mu4e-utils doc-view jka-compr image-mode image
mu4e-lists mu4e-vars message rmc puny rfc822 mml mml-sec epa derived epg
gnus-util rmail rmail-loaddefs mm-decode mm-bodies mm-encode mail-parse
rfc2231 rfc2047 rfc2045 mm-util ietf-drums mail-prsvr mailabbrev
mail-utils gmm-utils mailheader hl-line fringe mu4e-meta vc-git
diff-mode tex-info tex crm texinfo misearch multi-isearch dired-aux
term/xterm xterm server xcscope dired dired-loaddefs paredit
aggressive-indent fillcode company-jedi jedi-core python-environment epc
ctable concurrent company-racer deferred python cc-mode cc-fonts
cc-guess cc-menus cc-styles cc-align cc-cmds cc-engine cc-vars cc-defs
cc-bytecomp ws-butler cap-words superword subword fic-mode elec-pair
luis-iterm luis-apps luis-mail luis-modes luis-julia luis-rust
flycheck-rust flycheck json map rx subr-x luis-xml luis-make luis-scala
luis-sbt luis-java luis-lua luis-asm luis-org luis-c luis-python
luis-apache luis-swift luis-css luis-shell luis-latex luis-markdown
luis-text-wrap visual-fill-column adaptive-wrap luis-elisp luis-look
paren solarized-dark-theme solarized dash powerline powerline-separators
color powerline-themes luis-user-interaction luis-compile luis-movement
saveplace luis-modification company-keywords company-css
company-dabbrev-code company-dabbrev company-elisp find-func company
pcase luis-interactive time-date which-key flx-ido flx ido-vertical-mode
crm-custom ido-completing-read+ warnings memoize s cus-edit cus-start
cus-load minibuf-eldef ido luis-files projectile grep compile ibuf-ext
ibuffer ibuffer-loaddefs thingatpt tramp-cache tramp-sh tramp
tramp-compat tramp-loaddefs trampver ucs-normalize shell pcomplete
comint regexp-opt ansi-color ring parse-time format-spec recentf
tree-widget wid-edit autorevert filenotify luis-integration xt-mouse
cl-extra help-mode diminish use-package use-package-ensure
use-package-delight use-package-diminish use-package-bind-key bind-key
easy-mmode use-package-core luis-packages cl finder-inf tex-site edmacro
kmacro ess-generics info tool-bar package easymenu epg-config
url-handlers url-parse auth-source cl-seq eieio eieio-core cl-macs
eieio-loaddefs password-cache url-vars seq byte-opt gv bytecomp
byte-compile cconv luis-private benchmark-init advice cl-loaddefs cl-lib
benchmark-init-loaddefs mule-util tooltip eldoc electric uniquify
ediff-hook vc-hooks lisp-float-type tabulated-list replace newcomment
text-mode elisp-mode lisp-mode prog-mode register page menu-bar
rfn-eshadow isearch timer select 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 kqueue
multi-tty make-network-process emacs)

Memory information:
((conses 16 775479 32983)
 (symbols 48 45855 1)
 (miscs 40 109 347)
 (strings 32 166124 19659)
 (string-bytes 1 4804936)
 (vectors 16 91608)
 (vector-slots 8 2008071 76500)
 (floats 8 732 1467)
 (intervals 56 3942 24)
 (buffers 992 22))