[PATCH] regex: Add extra escapes to regular expressions in m4

[Siddhesh Poyarekar]

From: Siddhesh Poyarekar <siddh...@sourceware.org>

        * m4/regex.m4 (gl_REGEX): Add extra escape characters to
        regular expressions.
---

The m4 preprocessor eats up half the escape characters, so give it twice
as much.  I ran into this when running tests for glibc 2.29 release and
verified that this patch fixes the problem.

Siddhesh

 m4/regex.m4 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/m4/regex.m4 b/m4/regex.m4
index 35119c5c8..8e7efadff 100644
--- a/m4/regex.m4
+++ b/m4/regex.m4
@@ -204,7 +204,7 @@ AC_DEFUN([gl_REGEX],
                            & ~RE_CONTEXT_INVALID_DUP
                            & ~RE_NO_EMPTY_RANGES);
             memset (&regex, 0, sizeof regex);
-            s = re_compile_pattern ("[[:alnum:]_-]\\\\+$", 16, &regex);
+            s = re_compile_pattern ("[[:alnum:]_-]\\\\\\\\+$", 16, &regex);
             if (s)
               result |= 32;
 
@@ -220,7 +220,7 @@ AC_DEFUN([gl_REGEX],
                back reference.  */
             re_set_syntax (RE_SYNTAX_POSIX_EGREP);
             memset (&regex, 0, sizeof regex);
-            s = re_compile_pattern ("0|()0|\\1|0", 10, &regex);
+            s = re_compile_pattern ("0|()0|\\\\1|0", 10, &regex);
             if (!s || strcmp (s, "Invalid back reference"))
               result |= 64;
 
-- 
2.19.2