Make translation of quotes to curly in doc strings optional.

src/doc.c (traditional, prefer-unicode): new symbols.
(help-quote-translation): new variable.
(Fsubstitute_command_keys): make translation of quotes dependent on
`help-quote-translation'; also translate curly quotes back to ASCII
ones.

lisp/cus-start.el (top-level): Add a customization entry for
`help-quote-translation'.

1 files changed, 8 insertions, 1 deletions

diff --git a/lisp/cus-start.el b/lisp/cus-start.el
index 8740f075621..5dd36811436 100644
--- a/lisp/cus-start.el
+++ b/lisp/cus-start.el
@@ -220,7 +220,14 @@ Leaving \"Default\" unchecked is equivalent with specifying a default of
              (visible-bell display boolean)
              (no-redraw-on-reenter display boolean)
 
-             ;; dosfns.c
+             ;; doc.c
+             (help-quote-translation help
+                                     (choice
+                                      (const :tag "No translation" nil)
+                                      (const :tag "Translate curly single quotes to ASCII" traditional)
+                                      (const :tag "Translate ASCII single quotes to curly" prefer-unicode)))
+
+             ;; dosfns.c
              (dos-display-scancodes display boolean)
              (dos-hyper-key keyboard integer)
              (dos-super-key keyboard integer)