Merge pull request #98 from Batterii/pullrequest_85

Pullrequest 85 + test coverage

tests/test_response.py

@@ -941,7 +941,6 @@ def test_encode_content_gzip_notyet_gzipped():
     eq_(res.content_length, 23)
     eq_(res.app_iter, [
         b'\x1f\x8b\x08\x00\x00\x00\x00\x00\x02\xff',
-        b'',
         b'K\xcb\xcf\x07\x00',
         b'!es\x8c\x03\x00\x00\x00'
         ])
@@ -954,11 +953,22 @@ def test_encode_content_gzip_notyet_gzipped_lazy():
     eq_(res.content_length, None)
     eq_(list(res.app_iter), [
         b'\x1f\x8b\x08\x00\x00\x00\x00\x00\x02\xff',
-        b'',
         b'K\xcb\xcf\x07\x00',
         b'!es\x8c\x03\x00\x00\x00'
         ])
 
+def test_encode_content_gzip_buffer_coverage():
+    """this test is to provide 100% coverage of
+    response.Response.encode_content was necessary in order to get
+    pull request https://github.com/Pylons/webob/pull/85 into upstream
+    """
+    res = Response()
+    DATA = b"abcdefghijklmnopqrstuvwxyz0123456789" * 1000000
+    res.app_iter = io.BytesIO(DATA)
+    res.encode_content('gzip')
+    result = list(res.app_iter)
+    assert len("".join(result)) < len(DATA)
+
 def test_decode_content_identity():
     res = Response()
     res.content_encoding = 'identity'

webob/response.py

@@ -1277,8 +1277,18 @@ def gzip_app_iter(app_iter):
     for item in app_iter:
         size += len(item)
         crc = zlib.crc32(item, crc) & 0xffffffff
-        yield compress.compress(item)
-    yield compress.flush()
+
+        # The compress function may return zero length bytes if the input is
+        # small enough; it buffers the input for the next iteration or for a
+        # flush.
+        result = compress.compress(item)
+        if result:
+            yield result
+
+    # Similarly, flush may also not yield a value.
+    result = compress.flush()
+    if result:
+        yield result
     yield struct.pack("<2L", crc, size & 0xffffffff)
 
 def _error_unicode_in_app_iter(app_iter, body):