ox-html.el (org-html-use-unicode-chars): Delete.

* ox-html.el (org-html-use-unicode-chars): Delete.
(html, org-html-final-function): Update.

* org.texi (Publishing options): Don't mention
`org-html-use-unicode-chars'.

Thanks to Vladimir Alexiev for raising this.

doc/org.texi

@@ -14365,7 +14365,6 @@ however, override everything.
 @item @code{:html-todo-kwd-class-prefix}      @tab @code{org-html-todo-kwd-class-prefix}
 @item @code{:html-toplevel-hlevel}            @tab @code{org-html-toplevel-hlevel}
 @item @code{:html-use-infojs}                 @tab @code{org-html-use-infojs}
-@item @code{:html-use-unicode-chars}          @tab @code{org-html-use-unicode-chars}
 @item @code{:html-validation-link}            @tab @code{org-html-validation-link}
 @item @code{:html-viewport}                   @tab @code{org-html-viewport}
 @item @code{:html-xml-declaration}            @tab @code{org-html-xml-declaration}

etc/ORG-NEWS

@@ -543,6 +543,11 @@ Special ~comment~ value is no longer allowed.  It is possible to use a
 body filter to add comments about the creator at the end of the
 document instead.
 
+*** Removed option =org-html-use-unicode-chars=
+
+Setting this to non-nil was problematic as it converted characters
+everywhere in the buffer, possibly corrupting URLs.
+
 *** Removed option =org-babel-sh-command=
 
 This undocumented option defaulted to the value of =shell-file-name=

lisp/ox-html.el

@@ -161,7 +161,6 @@
     (:html-todo-kwd-class-prefix nil nil org-html-todo-kwd-class-prefix)
     (:html-toplevel-hlevel nil nil org-html-toplevel-hlevel)
     (:html-use-infojs nil nil org-html-use-infojs)
-    (:html-use-unicode-chars nil nil org-html-use-unicode-chars)
     (:html-validation-link nil nil org-html-validation-link)
     (:html-viewport nil nil org-html-viewport)
     (:html-inline-images nil nil org-html-inline-images)
@@ -608,13 +607,6 @@ Warning: non-nil may break indentation of source code blocks."
   :package-version '(Org . "8.0")
   :type 'boolean)
 
-(defcustom org-html-use-unicode-chars nil
-  "Non-nil means to use unicode characters instead of HTML entities."
-  :group 'org-export-html
-  :version "24.4"
-  :package-version '(Org . "8.0")
-  :type 'boolean)
-
 ;;;; Drawers
 
 (defcustom org-html-format-drawer-function (lambda (name contents) contents)
@@ -3500,9 +3492,6 @@ contextual information."
     (set-auto-mode t)
     (if (plist-get info :html-indent)
 	(indent-region (point-min) (point-max)))
-    (when (plist-get info :html-use-unicode-chars)
-      (require 'mm-url)
-      (mm-url-decode-entities))
     (buffer-substring-no-properties (point-min) (point-max))))