Before refontifying a region, remove any text properties we care about
so that we don't end up with stray properties. Additionally, make sure
to remove all the properties when deactivating the mode.
* lisp/emacs-lisp/subr-x.el (add-remove--display-text-property): New
function, extracted from...
(add-display-text-property): ... here.
(remove-display-text-property): New function.
* lisp/visual-wrap.el (visual-wrap--remove-properties): New function...
(visual-wrap-prefix-function, visual-wrap-prefix-mode): ... call it.
* test/lisp/emacs-lisp/subr-x-tests.el
(subr-x-test-remove-display-text-property): New test.
* test/lisp/visual-wrap-tests.el
(visual-wrap-tests/wrap-prefix-stickiness, visual-wrap-tests/cleanup):
New tests.
* doc/lispref/display.texi (Display Property): Document
'remove-display-text-property'.
* etc/NEWS: Announce 'remove-display-text-property' (bug#76018).
This makes sure we don't interfere with other display specs, e.g. for
images displayed in 'image-mode' (bug#73600).
* lisp/visual-wrap.el (visual-wrap--safe-display-specs): New variable.
(visual-wrap--display-property-safe-p): New function.
(visual-wrap--apply-to-line): Use 'pos-eol'; we don't want to respect
field boundaries here.
(visual-wrap-prefix-function): Check for unsafe display properties at
the end of the line and skip past them if present.
* test/lisp/visual-wrap-tests.el: New test file.
