fix history expansion to not perform quick substitution on a new line that's part of a quoted string; save the value of $_ around prompt string decoding

lib/readline/doc/history.3

@@ -6,9 +6,9 @@
 .\"	Case Western Reserve University
 .\"	chet.ramey@case.edu
 .\"
-.\"	Last Change: Thu Jan 19 17:20:59 EST 2023
+.\"	Last Change: Thu Dec 14 15:42:44 EST 2023
 .\"
-.TH HISTORY 3 "2023 January 19" "GNU History 8.2"
+.TH HISTORY 3 "2023 December 14" "GNU History 8.3"
 .\"
 .\" File Name macro.  This used to be `.PN', for Path Name,
 .\" but Sun doesn't seem to like that very much.
@@ -74,10 +74,21 @@ does when reading input,
 so that several words that would otherwise be separated 
 are considered one word when surrounded by quotes (see the
 description of \fBhistory_tokenize()\fP below).
+.PP
 History expansions are introduced by the appearance of the
 history expansion character, which is \^\fB!\fP\^ by default.
 Only backslash (\^\fB\e\fP\^) and single quotes can quote
 the history expansion character.
+.PP
+There is a special abbreviation for substitution, active when the
+\fIquick substitution\fP character (default \fB\(ha\fP)
+is the first character on the line.
+It selects the previous history list entry, using an event designator
+equivalent to \fB!!\fP,
+and substitutes one string for another in that line.
+It is described below under \fBEvent Designators\fP.
+This is the only history expansion that does not begin with the history
+expansion character.
 .SS Event Designators
 An event designator is a reference to a command line entry in the
 history list.

lib/readline/doc/hsuser.texi

@@ -316,6 +316,16 @@ also treated as quoted if it immediately precedes the closing double quote
 in a double-quoted string. 
 @end ifset
 
+There is a special abbreviation for substitution, active when the
+@var{quick substitution} character (default @samp{^})
+is the first character on the line.
+It selects the previous history list entry, using an event designator
+equivalent to @code{!!},
+and substitutes one string for another in that line.
+It is described below (@pxref{Event Designators}).
+This is the only history expansion that does not begin with the history
+expansion character.
+
 @ifset BashFeatures
 Several shell options settable with the @code{shopt}
 builtin (@pxref{The Shopt Builtin}) may be used to tailor

lib/readline/doc/version.texi

@@ -5,7 +5,7 @@ Copyright (C) 1988-2023 Free Software Foundation, Inc.
 @set EDITION 8.3
 @set VERSION 8.3
 
-@set UPDATED 3 November 2023
-@set UPDATED-MONTH November 2023
+@set UPDATED 14 December 2023
+@set UPDATED-MONTH December 2023
 
-@set LASTCHANGE Fri Nov  3 12:04:26 EDT 2023
+@set LASTCHANGE Thu Dec 14 15:45:46 EST 2023

lib/readline/histexpand.c

@@ -950,7 +950,7 @@ history_expand (const char *hstring, char **output)
   /* The quick substitution character is a history expansion all right.  That
      is to say, "^this^that^" is equivalent to "!!:s^this^that^", and in fact,
      that is the substitution that we do. */
-  if (hstring[0] == history_subst_char)
+  if ((history_quoting_state != '\'' || history_quotes_inhibit_expansion == 0) && hstring[0] == history_subst_char)
     {
       string = (char *)xmalloc (l + 5);