Add a way to disable substitution of command keys in help strings

* src/keyboard.c (help_echo_substitute_command_keys): New function.
(help_echo_echo, parse_menu_item): Use it.
(syms_of_keyboard): Define Qhelp_echo_inhibit_substitution.

* doc/lispref/text.texi (Special Properties), etc/NEWS: Document
the effect of 'help-echo-inhibit-substitution'.

1 files changed, 20 insertions, 3 deletions

diff --git a/src/keyboard.c b/src/keyboard.c
index db583ec530e..56ab79068ad 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -2019,6 +2019,22 @@ make_ctrl_char (int c)
   return c;
 }
 
+/* Substitute key descriptions and quotes in HELP, unless its first
+   character has a non-nil help-echo-inhibit-substitution property.  */
+
+static Lisp_Object
+help_echo_substitute_command_keys (Lisp_Object help)
+{
+  if (STRINGP (help)
+      && SCHARS (help) > 0
+      && !NILP (Fget_text_property (make_fixnum (0),
+                                    Qhelp_echo_inhibit_substitution,
+                                    help)))
+    return help;
+
+  return Fsubstitute_command_keys (help);
+}
+
 /* Display the help-echo property of the character after the mouse pointer.
    Either show it in the echo area, or call show-help-function to display
    it by other means (maybe in a tooltip).
@@ -2078,7 +2094,7 @@ show_help_echo (Lisp_Object help, Lisp_Object window, Lisp_Object object,
   if (STRINGP (help) || NILP (help))
     {
       if (!NILP (Vshow_help_function))
-        call1 (Vshow_help_function, Fsubstitute_command_keys (help));
+        call1 (Vshow_help_function, help_echo_substitute_command_keys (help));
       help_echo_showing_p = STRINGP (help);
     }
 }
@@ -7670,7 +7686,7 @@ parse_menu_item (Lisp_Object item, int inmenubar)
       if (CONSP (item) && STRINGP (XCAR (item)))
         {
           ASET (item_properties, ITEM_PROPERTY_HELP,
-                Fsubstitute_command_keys (XCAR (item)));
+                help_echo_substitute_command_keys (XCAR (item)));
           start = item;
           item = XCDR (item);
         }
@@ -7734,7 +7750,7 @@ parse_menu_item (Lisp_Object item, int inmenubar)
                 {
                   Lisp_Object help = XCAR (item);
                   if (STRINGP (help))
-                    help = Fsubstitute_command_keys (help);
+                    help = help_echo_substitute_command_keys (help);
                   ASET (item_properties, ITEM_PROPERTY_HELP, help);
                 }
               else if (EQ (tem, QCfilter))
@@ -11455,6 +11471,7 @@ syms_of_keyboard (void)
   /* Tool-bars.  */
   DEFSYM (QCimage, ":image");
   DEFSYM (Qhelp_echo, "help-echo");
+  DEFSYM (Qhelp_echo_inhibit_substitution, "help-echo-inhibit-substitution");
   DEFSYM (QCrtl, ":rtl");
 
   staticpro (&item_properties);