* search.c (Freplace_match): Treat \? in the replacement text literally.

Fixes: debbugs:8161

3 files changed, 13 insertions, 1 deletions

diff --git a/etc/NEWS b/etc/NEWS
index b7fb10881ff..e95ce5ac155 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -482,6 +482,10 @@ inefficiency, and not namespace-clean.
 
 * Incompatible Lisp Changes in Emacs 24.2
 
+** If the NEWTEXT arg to `replace-match' contains a substring "\?",
+that substring is inserted literally even if the LITERAL arg is
+non-nil, instead of causing an error to be signaled.
+
 +++
 ** Docstrings starting with `*' no longer indicate user options.
 Only variables defined using `defcustom' are considered user options.
diff --git a/src/ChangeLog b/src/ChangeLog
index 8d13944b633..d760dd1df78 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2012-08-05  Lawrence Mitchell  <wence@gmx.li>
+
+        * search.c (Freplace_match): Treat \? in the replacement text
+        literally (Bug#8161).
+
 2012-08-05  Chong Yidong  <cyd@gnu.org>
 
         * term.c (Vsuspend_tty_functions, Vresume_tty_functions):
diff --git a/src/search.c b/src/search.c
index 480d0b75c70..004e599be9c 100644
--- a/src/search.c
+++ b/src/search.c
@@ -2226,6 +2226,9 @@ Otherwise treat `\\' as special:
   `\\N' means substitute what matched the Nth `\\(...\\)'.
        If Nth parens didn't match, substitute nothing.
   `\\\\' means insert one `\\'.
+  `\\?' is treated literally
+       (for compatibility with `query-replace-regexp').
+  Any other character following `\\' signals an error.
 Case conversion does not apply to these substitutions.
 
 FIXEDCASE and LITERAL are optional arguments.
@@ -2428,7 +2431,7 @@ since only regular expressions have distinguished subexpressions.  */)
                     }
                   else if (c == '\\')
                     delbackslash = 1;
-                  else
+                  else if (c != '?')
                     error ("Invalid use of `\\' in replacement text");
                 }
               if (substart >= 0)