From: Lars Ingebrigtsen <larsi@gnus.org>
Date: Sat, 3 Aug 2019 14:00:20 +0000 (+0200)
Subject: Fix error message in replace-match for subexpressions
X-Git-Tag: emacs-27.0.90~1733
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=18e163fd3455deaa30b1effd19f51a5094bc0885;p=emacs.git

Fix error message in replace-match for subexpressions

* src/search.c (Freplace_match): Output a more understandable
error message when replacing a subexpression (bug#19208).
---

diff --git a/src/search.c b/src/search.c
index 2fa8b277195..0e2ae059e81 100644
--- a/src/search.c
+++ b/src/search.c
@@ -2404,6 +2404,12 @@ since only regular expressions have distinguished subexpressions.  */)
 	args_out_of_range (subexp, make_fixnum (search_regs.num_regs));
     }
 
+  /* Check whether the subexpression to replace is greater than the
+     number of subexpressions in the regexp. */
+  if (sub > 0 && search_regs.start[sub] == -1)
+    args_out_of_range (build_string ("Attempt to replace regexp subexpression that doesn't exist"),
+		       subexp);
+
   /* Sanity check to see whether the text to replace is present in the
      buffer/string. */
   if (NILP (string))