Use .read1() if available when using GzipFile

.travis.yml

@@ -11,9 +11,6 @@ env:
  - TOXENV=py33
  - TOXENV=py35
  - TOXENV=docs
-matrix:
-  allow_failures:
-    - env: TOXENV=py35
 install:
  - pip install -U tox twine wheel codecov
 script: tox

scrapy/utils/gz.py

@@ -4,30 +4,38 @@ try:
     from cStringIO import StringIO as BytesIO
 except ImportError:
     from io import BytesIO
-
+from io import UnsupportedOperation
 from gzip import GzipFile
 
+class ReadOneGzipFile(GzipFile):
+    def readone(self, size=-1):
+        try:
+            return self.read1(size)
+        except UnsupportedOperation:
+            return self.read(size)
 
 def gunzip(data):
     """Gunzip the given data and return as much data as possible.
 
     This is resilient to CRC checksum errors.
     """
-    f = GzipFile(fileobj=BytesIO(data))
+    f = ReadOneGzipFile(fileobj=BytesIO(data))
     output = b''
     chunk = b'.'
     while chunk:
         try:
-            chunk = f.read(8196)
+            chunk = f.readone(8196)
             output += chunk
         except (IOError, EOFError, struct.error):
             # complete only if there is some data, otherwise re-raise
             # see issue 87 about catching struct.error
             # some pages are quite small so output is '' and f.extrabuf
             # contains the whole page content
-            if output or f.extrabuf:
-                output += f.extrabuf
-                break
+            if output or getattr(f, 'extrabuf', None):
+                try:
+                    output += f.extrabuf
+                finally:
+                    break
             else:
                 raise
     return output

tests/test_squeues.py

@@ -34,7 +34,7 @@ class MarshalFifoDiskQueueTest(t.FifoDiskQueueTest):
         # Trigger Twisted bug #7989
         import twisted.persisted.styles  # NOQA
         q = self.queue()
-        self.assertRaises(ValueError, q.push, lambda x: x)
+        self.assertRaises((ValueError, AttributeError), q.push, lambda x: x)
 
 class ChunkSize1MarshalFifoDiskQueueTest(MarshalFifoDiskQueueTest):
     chunksize = 1
@@ -114,7 +114,7 @@ class MarshalLifoDiskQueueTest(t.LifoDiskQueueTest):
         # Trigger Twisted bug #7989
         import twisted.persisted.styles  # NOQA
         q = self.queue()
-        self.assertRaises(ValueError, q.push, lambda x: x)
+        self.assertRaises((ValueError, AttributeError), q.push, lambda x: x)
 
 
 class PickleLifoDiskQueueTest(MarshalLifoDiskQueueTest):