Fail decompression of small bogus content.

.travis.yml

@@ -8,7 +8,7 @@ python:
 
 sudo: false
 install:
-  - "pip install -U pip setuptools"
+  - "pip install -U pip 'setuptools!=26.*'"
   - "pip install ."
   - "pip install -r test_requirements.txt"
   - "pip install flake8"

src/brotli/brotli.py

@@ -82,7 +82,9 @@ def decompress(data):
     :param data: A bytestring containing Brotli-compressed data.
     """
     d = Decompressor()
-    return d.decompress(data)
+    data = d.decompress(data)
+    d.finish()
+    return data
 
 
 def compress(data,
@@ -433,15 +435,28 @@ def flush(self):
         Complete the decompression, return whatever data is remaining to be
         decompressed.
 
-        This action also resets the decompression state, allowing the
-        decompressor to be used again.
-
         .. deprecated:: 0.4.0
 
             This method is no longer required, as decompress() will now
             decompress eagerly.
 
         :returns: A bytestring containing the remaining decompressed data.
         """
+        return b''
+
+    def finish(self):
+        """
+        Finish the decompressor. As the decompressor decompresses eagerly, this
+        will never actually emit any data. However, it will potentially throw
+        errors if a truncated or damaged data stream has been used.
+
+        Note that, once this method is called, the decompressor is no longer
+        safe for further use and must be thrown away.
+        """
+        assert (
+            lib.BrotliDecoderHasMoreOutput(self._decoder) == lib.BROTLI_FALSE
+        )
+        if lib.BrotliDecoderIsFinished(self._decoder) == lib.BROTLI_FALSE:
+            raise Error("Decompression error: incomplete compressed stream.")
 
         return b''

test/test_simple_decompression.py

@@ -33,6 +33,7 @@ def test_decompressobj(simple_compressed_file):
     o = brotli.Decompressor()
     data = o.decompress(compressed_data)
     data += o.flush()
+    data += o.finish()
 
     assert data == uncompressed_data
 
@@ -53,6 +54,7 @@ def test_drip_feed(simple_compressed_file):
         outdata.append(o.decompress(compressed_data[i:i+1]))
 
     outdata.append(o.flush())
+    outdata.append(o.finish())
 
     assert b''.join(outdata) == uncompressed_data
 
@@ -68,9 +70,10 @@ def test_streaming_decompression_fails_properly_on_garbage(exception_cls):
 
 
 @pytest.mark.parametrize('exception_cls', [brotli.Error, brotli.error])
-def test_decompression_fails_properly_on_garbage(exception_cls):
+@pytest.mark.parametrize('bogus', (b'some random garbage', b'bogus'))
+def test_decompression_fails_properly_on_garbage(bogus, exception_cls):
     """
     Garbage data properly fails decompression.
     """
     with pytest.raises(exception_cls):
-        brotli.decompress(b'some random garbage')
+        brotli.decompress(bogus)