Perl: creating input and error streams if closed.

Application handler can do anything with a stream object (including close it).
Once the stream is closed, Unit creates a new stream.

This closes #616 issue on GitHub.

test/perl/input_buffered_read/psgi.pl

@@ -0,0 +1,17 @@
+use FileHandle;
+
+my $app = sub {
+    my ($environ) = @_;
+
+    $environ->{'psgi.input'}->read(my $body, 1024);
+
+    open my $io, "<", \$body;
+
+    # This makes $io work as FileHandle under 5.8, .10 and .11.
+    bless $io, 'FileHandle';
+
+    $environ->{'psgix.input.buffered'} = 1;
+    $environ->{'psgi.input'} = $io;
+
+    return ['200', ['Content-Length' => length $body], [$body]];
+};

test/perl/input_close/psgi.pl

@@ -0,0 +1,8 @@
+my $app = sub {
+    my ($environ) = @_;
+
+    $environ->{'psgi.input'}->read(my $body, 1024);
+    $environ->{'psgi.input'}->close();
+
+    return ['200', ['Content-Length' => length $body], [$body]];
+};

test/test_perl_application.py

@@ -100,6 +100,28 @@ class TestPerlApplication(TestApplicationPerl):
             self.post(body='0123456789')['body'] == '0123456789'
         ), 'input read parts'
 
+    def test_perl_application_input_buffered_read(self):
+        self.load('input_buffered_read')
+
+        assert (
+            self.post(body='012345')['body'] == '012345'
+        ), 'buffered read #1'
+
+        assert (
+            self.post(body='9876543210')['body'] == '9876543210'
+        ), 'buffered read #2'
+
+    def test_perl_application_input_close(self):
+        self.load('input_close')
+
+        assert (
+            self.post(body='012345')['body'] == '012345'
+        ), 'input close #1'
+
+        assert (
+            self.post(body='9876543210')['body'] == '9876543210'
+        ), 'input close #2'
+
     @pytest.mark.skip('not yet')
     def test_perl_application_input_read_offset(self):
         self.load('input_read_offset')