Treat help strings like other doc strings

* doc/lispref/text.texi (Special Properties), etc/NEWS: Document this.
* lisp/epa.el (epa--select-keys): Remove no-longer-needed calls to
substitute-command-keys.
* src/keyboard.c (show_help_echo, parse_menu_item): Call
substitute-command-keys on the help string before displaying it.

1 files changed, 8 insertions, 0 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 4ab80f53fd7..85df71607ee 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -886,6 +886,7 @@ when signaling a file error.  For example, it now reports "Permission
 denied" instead of "permission denied".  The old behavior was problematic
 in languages like German where downcasing rules depend on grammar.
 
++++
 ** substitute-command-keys now replaces quotes.
 That is, it converts documentation strings' quoting style as per the
 value of the new custom variable ‘help-quote-translation’: ?‘ means
@@ -1008,6 +1009,7 @@ directory at point.
 *** New macros `thread-first' and `thread-last' allow threading a form
     as the first or last argument of subsequent forms.
 
++++
 ** Documentation strings now support quoting with curved single quotes
 ‘like-this’ in addition to the old style with grave accent and
 apostrophe `like-this'.  The new style looks better on today's displays.
@@ -1019,6 +1021,12 @@ key works) by typing ‘A-[’ and ‘A-]’.  As described above under
 string quotes.
 
 +++
+** show-help-function's arg is converted via substitute-command-keys
+before being passed to the function.  Help strings, help-echo
+properties, etc. can therefore contain command key escapes and
+quotation marks.
+
++++
 ** Time-related changes:
 
 *** Time conversion functions now accept an optional ZONE argument