[PATCH] aclocal: handle both # and dnl for serial number lines

Instead of only accepting comment lines that start with # for serial lines, also
accept dnl.
---
 bin/aclocal.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bin/aclocal.in b/bin/aclocal.in
index 224f8c7..1c5add5 100644
--- a/bin/aclocal.in
+++ b/bin/aclocal.in
@@ -151,7 +151,7 @@ my $ac_require_rx = "AC_REQUIRE\\((?:\\[([^]]+)\\]|([^],)\n]+))\\)";
 my $m4_include_rx = "(m4_|m4_s|s)include\\((?:\\[([^]]+)\\]|([^],)\n]+))\\)";
 
 # Match a serial number.
-my $serial_line_rx = '^#\s*serial\s+(\S*)';
+my $serial_line_rx = '^(?:#|dnl)\s*serial\s+(\S*)';
 my $serial_number_rx = '^\d+(?:\.\d+)*$';
 
 # Autoconf version.  This variable is set by 'trace_used_macros'.
-- 
2.8.1