gnu: automake: Adjust to deal with Perl 5.22.

Fixes <http://bugs.gnu.org/22375>.

* gnu/packages/patches/automake-regexp-syntax.patch: New file.
* gnu/packages/autotools.scm (automake)[source]: Use it.
* gnu-system.am (dist_patch_DATA): Add it.

1 files changed, 34 insertions, 0 deletions

diff --git a/gnu/packages/patches/automake-regexp-syntax.patch b/gnu/packages/patches/automake-regexp-syntax.patch
new file mode 100644
index 0000000000..2e965c8c50
--- /dev/null
+++ b/gnu/packages/patches/automake-regexp-syntax.patch
@@ -0,0 +1,34 @@
+From <https://lists.gnu.org/archive/html/automake-patches/2015-07/msg00000.html>.
+See also <http://bugs.gnu.org/22372>.
+
+From 34163794a58b5bd91c5d6bd9adf5437571c7a479 Mon Sep 17 00:00:00 2001
+From: Pavel Raiskup <praiskup@redhat.com>
+Date: Tue, 7 Jul 2015 10:54:24 +0200
+Subject: [PATCH] bin/automake: escape '{' in regexp pattern
+
+Based on perlre(1) documentation:
+.. in Perl v5.26, literal uses of a curly bracket will be required
+to be escaped, say by preceding them with a backslash ("\{" ) or
+enclosing them within square brackets ("[{]") ..
+
+References:
+https://bugzilla.redhat.com/1239379
+
+* bin/automake.in (substitute_ac_subst_variables): Escape the
+occurrence of '{' character.
+---
+ bin/automake.in | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/bin/automake.in b/bin/automake.in
+index 0c29184..c294ced 100644
+--- a/bin/automake.in
++++ b/bin/automake.in
+@@ -3898,7 +3898,7 @@ sub substitute_ac_subst_variables_worker
+ sub substitute_ac_subst_variables
+ {
+   my ($text) = @_;
+-  $text =~ s/\${([^ \t=:+{}]+)}/substitute_ac_subst_variables_worker ($1)/ge;
++  $text =~ s/\$\{([^ \t=:+{}]+)}/substitute_ac_subst_variables_worker ($1)/ge;
+   return $text;
+ }