(m4_re_escape): Escape ?, ^, \, $ too.

diff --git a/lib/m4sugar/m4sugar.m4 b/lib/m4sugar/m4sugar.m4
index 1e828e20c9cea430aad65d752fa0b635a1303879..741a333f2e05c15a1dbbf55d4f4ded4b66ff8668 100644 (file)
--- a/lib/m4sugar/m4sugar.m4
+++ b/lib/m4sugar/m4sugar.m4
@@ -1318,10 +1318,10 @@ m4_defn([m4_cr_digits])dnl
 
 # m4_re_escape(STRING)
 # --------------------
-# Escape BRE active characters in STRING.
+# Escape RE active characters in STRING.
 m4_define([m4_re_escape],
 [m4_bpatsubst([$1],
-             [[][+*.]], [\\\&])])
+             [[][*+.?\^$]], [\\\&])])
 
 
 # m4_re_string