Fix issue #563 (Count only one match per line for --count option, not all the matches)

ack

@@ -891,11 +891,9 @@ sub count_matches_in_resource {
             }
         }
         else {
-            my $content = do {
-                local $/;
-                <$fh>;
-            };
-            $nmatches =()= ($content =~ /$opt_regex/og);
+            while ( <$fh> ) {
+                ++$nmatches if (/$opt_regex/o);
+            }
         }
         close $fh;
     }

t/issue563.t

@@ -0,0 +1,25 @@
+
+#!perl -T
+
+# https://github.com/petdance/ack2/issues/563
+
+use strict;
+use warnings;
+use lib 't';
+
+use Test::More tests => 4;
+use Util;
+
+prep_environment();
+
+my @result = pipe_into_ack(\'aa', '-c', 'a');
+is( $result[0], 1, 'Only one match counts per line' );
+
+@result = pipe_into_ack(\'abcdgh', '-c', 'ab(c(d|e)|ef)gh');
+is( $result[0], 1, 'Nested groups with alternation in pattern match only once per line' );
+
+@result = pipe_into_ack(\'abcdgh', '-c', 'abc(((d)))gh');
+is( $result[0], 1, 'Nested groups in pattern match only once per line' );
+
+@result = pipe_into_ack(\'abcdgh', '-c', 'abc(d)(g)h');
+is( $result[0], 1, 'Many groups in pattern match only once per line' );